Despite my best efforts I have upgradeitis. I have a Cremina and it delivers wonderful espresso and I have no complaints. I have no reason to add another machine.. someone should have warned me that this hobby would create unreasonable desire for new gear.

But my situation is this: eventually what I really want (no logic or experience, just my heart telling me) is a italian commercial spring lever like the Izzo leva. This won't fit in my current kitchen (can't plumb it) so that plan will have to wait for my next house which will be a few years down the road at least. In the meantime, I'd like a non-lever for convenience and to accompany the Cremina.
So I don't love the aesthetics of e61 machines. I am very impressed with the Decent, but I am also certain that it offers too many options and parameters for my personality (I really will go down the rabbit hole). So I'm currently considering the Linea Mini and the Olympia Maximatic. Certainly the Linea offers commercial components and temperature perfection but the Maxi will pair so nicely with the Cremina. Another consideration is that if I get a Linea I will certainly sell it someday when I buy the big lever... but a Maximatic can hang around because it's so small and handy.

For those of you experienced with some of these machines, do you have any advice?

Get the lever you want and a kit to run it off a 5 gal. bottle

That's a good idea but hiding that bottle will be a challenge.

Whenever I think about buying a new machine, I remind myself that my Cremina is very well made, super simple in design, and requires very little maintenance. I've owned several HX and double boiler machines over the years, and while they could bang out shots faster, they also required a lot more daily, weekly, and monthly maintenance. That makes them much less convenient to me.

I'd agree that most any HX would be a step down in experience from a well-built and well-understood lever like the Cremina. HX machines are fiddly beasts for temperature control and take 40-60 minutes to warm up.

No matter HX or DB, for me, adjustable PI and flow management have become high-value features. I can much more easily pull "drip" roast SOs than I could on a "9-bar fits all" machine. You've probably internalized PI and flow control in your Cremina technique. There's a lot to be said for the skill of a good, lever-machine operator, especially a manual one.

Of those listed, Izzo leva. If you can stretch to a Londinium R, I would.

Looks like you already have a Cremina. The first two don't give you the flow control you already have with a direct lever. The Londinium R or the upcoming 24, will give you pre infusion and a modicum of flow control, (albeit without the direct feel you already have), PLUS one more thing the Cremina doesn't... temperature stability, so a win. If you went with the others, you would gain temperature stability but lose flow control and pre infusion.

After having BOTH flow control and temperature stability, I in the same machine, I wouldn't want to be without either.

-Peter

I have an hx as well , great machine but so much more stuff to do than with a cremina. Noise for one, Cremina's are sooo quiet! Pumps not so much unless you go rotary.

I can't stand the look of the new machines, too much stainless or chrome for me. You could get a Salvatore spring lever or e61 and get some very nice style since you mentioned Maximatic. I have a salvatore famosa which is a fancier Maximatic works great.

I'm convinced that it is possible for a disciplined person to run a big lever without plumbing it in. You need to remove the vacuum breaker, and then you can fill the boiler when it has cooled down and under a vacuum, by submerging the steam wand in a jug and opening the valve. It pulls a very deep vacuum when it is cooled doen to room temperature. I tested this with my Lambro and I could easily overfill my boiler with the vacuum it pulled.

If the boiler of your Cremina is large enough, you can try to see if you can make this workflow work for you.

Assuming your seals are good a vacuum breaker is hardly necessary. Once purged, there is not much air entering the system.

If I were you, I'd get the Decent that you dismissed earlier. Sounds like you will play around, and that's possibly what's missing from your current machines. That will hopefully keep you busy for a while.

If you're just looking for a pride of ownership thing - get the La Marzocco - it seems like owners of that machine are always happy with their purchases.

My Pompei has been out of order for a few weeks waiting for a replacement part. In the meantime I used the vintage Cremina.
Since a week or so my pompei is back up and running. Yesterday I parted woth the Cremina . With a BIG smile on my face.
Nothing beats the convenience of a big commercial machine.
The Cremina made great espresso. And steaming wasn't an issue either. And I love the looks of it.Best looking machine out there IMHO.
But the routine it requires will never be my cup of tea.