I've been exclusively using a K2 for my cheap-but-decent-enough setup at work (along with a Breville Dedica) and have found it to be pretty consistent. You do occasionally get some larger particles that slip through, but not enough to create any channeling issues, and it's easy enough to use. Compared to my 1ZPresso J Max, I find it for 1/3 the price it does a great job, especially since I don't have the super-sophisticated palette that would notice any really subtle differences.
Unrelated, is it possible to follow @coffee@a.gup.pe from Lemmy? I've tried from both the web UI and Voyager and haven't been able to get it to work -- this ticket suggests it didn't work as of September, but wanted to check in.