The ssp flats just require careful prep and a well-dialed in grind. You are also more likely to need to adjust the grind over the course of a week then you would a conical. The clumping is a non-issue as they will easily disperse with wdt (vs the clumping from a grinder like the rancilio Rocky). They extract a really nice espresso from light roast coffees, but if I was only drinking med to dark roast coffee I'd just stick with a conical. Just not worth the hassle.

With that said, Denis' shuriken burrs, for me and my usage, are a game changer in the large flat burr world. Easier to dial in, less sensitive to grind adjustments, better looking extractions, more predictable flow without the puck degradation that was typical of the ssp burrs, and, most importantly, better end results in the cup. Just to say, if I were looking to purchase a monolith, I'd be prioritizing the shuriken burrs.

Shuriken grinds out of a flat max:

Throwing in my two cents here:

I have a first production run Flat that came with the original Mythos burrs. After a few months I found that I didn't have to use RDT or WDT (evidently, we have enough ambient humidity to minimize static.) I upgraded to the SSP burrs, and while the taste was better, I experienced a significant increase in clumping. As others have said, these were the type of clumps that fell apart as soon as they were touched. I pretty-much ignored them and only had occasional spritzes. Sometimes I used WDT to break up the clumps, but I don't think that made much difference. My WDT tool is a mini-whisk (I'm skeptical about the ability of thin needles to really mix grinds, but I'm in the minority on that I'm sure. )

When I got the SSP burrs, I started out using a Lev-Tamp that I got from Kafatek. Later, I switched to a BT Wedge leveling tool I got from LM. Didn't make a difference in the pours, though I probably ground a little finer. But 3 years ago or so I switched to pulling singles almost 100% of the time, and went back to using a standard tamper because there are no 41mm levelers. Although I can grind directly into the funnel/basket, I use a Kafatek catch-cup. After grinding, I shake the grounds and stir them with the whisk. Then I put the funnel on upside-down, lay the PF over that, and invert the assembly in one smooth motion. No doubt, this does a good job mixing the grinds.

I upgraded to the Shuriken LM burrs when they became available. They produce *way* fewer clumps than the SSP burrs, and any clumps they do produce are much smaller. I'm using RDT, though I'm not sure it's necessary. I'm using an IMS precision 7g basket, and the pours are perfect or near-perfect every time. One thing I think helps with that is to use my WDT tool to level and push grounds to the edge of the basket to make sure there's a good seal with the basket, and leave a depression in the middle of the grounds before tamping. This avoids halo extractions. Not to beat a dead horse, but the mini-whisk is perfect for that task.

Note that prior to distributing the grounds, I tap the PF once on the counter to settle the grounds. After distribution, I tap the PF three more times before tamping. All that tapping seems to help.

If you stay with medium or dark roasts, you might consider the Shuriken MD burrs. Otherwise, the LM or SW burrs would be a significant upgrade from the SSP burrs.

FWIW, I ran 10 lbs of beans through all three sets of burrs before I used them. They continued to break in and get better for a couple of months.

Another factor is preinfusion and peak pressure. A peak pressure of 9 bar puts quite a lot of demand on the puck.

A grinder like this requires very solid puck prep - the fines distribution in a conical like Niche will work to slow down your flow and make it easier to avoid disintegrating your puck. Monoliths (with ssps) are much more unimodal and as such less forgiving for channeling. On the other hand the grinder should be much more forgiving when it comes to taste i.e. you should have a much wider range of grind at which the coffee will taste fantastic. At least that was my experience going to a Max from a Niche. That said, I drink light roasts and this grinder was pretty much designed for that - if I drank dark, or medium dark roasts I would've stuck with a niche as coffee like that doesn't benefit from flavour separation and would just taste harsh.

I haven't felt the need to switch to Shurikens so I cannot speak for those. But mostly as someone who has switched grinders too many times to count, give it a week or two before you complain or come to conclusions. There is always an adjustment period.

I can't give you all the answers you seek unfortunately but I can only tell you that this has been my experience - I find the max (and the other flat burr grinders such as the SJ with SSP espresso burrs I had before) tend to highlight the harsh more burnt flavours in a dark roast along with the other flavours, and it tastes more unpleasant. And yes they produce less body as well. That said I almost never drink dark roasts and for what I consider medium, I found the Max good enough that I didn't feel the need to keep the Niche as I had intended to do initially. The niche was still a great little grinder though.

I think Grind quality and flavour clarity should be higher for the Monolith, however, it may be less forgiving, conical burr grinders are pretty forgiving in terms of getting the distribution and puck prep, and grind size just right I find on my Monolith Flat with the LM Shuriken burrs they do a good job for a variety of roasts levels and is a bit more forgiving than a lot of grinders, but a lower clarity burr like those found on Eureka grinders or Conical grinders may be better for darker roasts.
Not sure which SSP burrs your Monolith has, but I find with the 64mm SSP burrs I've tried (in DF64s and P64) they're higher clarity and not ideal for darker roasts (flavour wise), and a conical grinder like the Niche Zero is best for darker roasts so it kinda has an advantage there.

*Update: Also wanted to note since you mentioned clumping, the Monolith as far as I can tell doesn't have a de-clumper which helps keep retention low, Niche may be the same actually but conical burrs are different behaving usually, so even on my Monolith flat with the Shuriken burrs I do see more clumping than with some grinders like on the Lagom p64, not sure if it makes a difference or not, but I do use a needle tool, so that stirs up / redistributes and breaks up those clumps.

Some flat burr grinders are better than others for dark roasts, Eureka tends to blend flavours together more than even the Stock Italmill burrs on a DF64, so you get less clarity in light roasts and flavours are less obviously defined, but it works really nicely in medium-->Darker roast levels, just blending it to make an overall pleasant flavour, my theory is that the darker roasts generally do NOT have a good flavour so you don't want clarity
Usually those low clarity grinders are worse for coarser brew methods I find. I think the fine particles over extract and add bitterness and obstruct the clarity of flavour in coarser brew methods. But in espresso it adds to the body.

ojt wrote:I've always wondered about this statement, is it really so? Some adamantly believe that flat burrs specifically would be better for dark roast, some say the contrary. Also, why would a good grind size particle distribution not help with dark roasts? Ok the most unimodal burrs out there perhaps are not a good idea Some fines are needed for espresso, imho, and in fact I would say this a matter of taste for light roasts too. But (with some fines) wouldn't a more unimodal grind even out the harshness? Or at least lessen the risk of excess bitterness and ensure you get the most out of your beans. Sure a grind with tons of finea s would probably make for a more gooey thick espresso, perhaps?

I've had a max for a few years now, pre shurikan.

When I got it I used the included basket and very first shots were amazing. Went back to vst and it was impossible.

Machine wore in over the next few months and my puck prep changed, now I get good shots with vst.

I don't need to wdt or rdt, grind into portafilter, swish grounds around to smooth them, then 3-5 hard taps on counter. The taps disappear the clumps. Then a light tamp and pull shot. If the clumps don't vanish then I stir it all up with needle tool, but that's a coffee issue.

By far biggest concern for me are minuscule (1/10 of a mark) grind adjustments and weigh beans to 0.1g. The grind changes through the week as the beans age. Using 21.5 in the vst 22g basket.