I counted about 13 seconds to grind that mound. Is your Rocky really that fast? Wow. I remember my Mazzer Mini taking more like 17 seconds. It could be the video quality, but that really does look like bad clumping. On the other hand, dosers can take care of that pretty easily, and clumping also doesn't ALWAYS cause poor extractions. I recall reading, for example, in the Titan Grinder Project, that while the conicals would sometimes clump as bad as a Mazzer Mini, they didn't show it the same way in their pours, and it didn't effect the quality.
Still, I doubt you will find a grinder faster than the Super Jolly (with Dura-mills) in your budget. I am very spoiled to its 5-7 second grinds. If you want something truly serious, there's the Major... I fear that thing. After I bought my Super Jolly, I saw a Major on eBay and had a moment of regret. But then I thought, hmm. I think I would waste a TON of coffee with a grinder that fast (say, 3 seconds for a double)... The timing errors get a lot more significant with that kind of speed.
I know what you mean about budgeting--I had a Silvia for a little while, and I have to admit that If I had a Super Jolly and a Silvia and I were thinking of an upgrade, I would go for the machine upgrade, either HX or probably double boiler. After you get a Mazzer Mini, you start to see really diminishing returns on grinders. I thought the Super Jolly was a big upgrade, especially in terms of convenience (faster, fewer botched shots), but I don't think it gets much better than that, even with big conicals or electronics--you mostly just get more cleanliness, slight speed improvements (or even a speed hit on 64mm conicals... I think the Macap MXKR is as slow as a Mini), and only somewhat noticeable cup improvement. But Silvia is a seriously crippled machine in terms of convenience.
I think you've rightly identified your upgrade need as it is--the Rocky is the weak point right now, but when you get a Super Jolly class grinder, it might well not be worth it to have anything better till you get a less... tedious machine. On the other hand, I know of at least one
crazy dude/living legend who still has a Silvia for his machine, and a Robur and Versalab for grinders... I think his Robur is the big 3-Phase 220V, too
