I have a 2.25" Mendo Mulcher, which I use for my Volcano. It grinds to medium consistency, which I think works well. It can tear through just about anything, regardless of moisture content, and has capacity to grind for two loads (or one fat joint).
As has been pointed out, the lip around the screen traps a lot of kief. However, the grinder needs to be cleaned every so often so the screen continues to work, and I find an occasional ISO wash does the trick, so you get all of the other trapped kif back, too. So, it doesn't bother me that much that it's stuck there, as I know I'll get it back eventually. It's not like there are any parts where kief would be dropping out when you unscrew the sections (unless you've got it upside down).
It does not have a gasket between the magnetic top and the screen section, so you've got aluminum-on-aluminum when you turn it. There's a lip there, so there's no way for aluminum shavings to end up in the grinder chamber, but a gasket still would have been nice.
I'm very happy with my grinder. If I were to lose it, I'd get another one immediately.