I have three of their kits, all of which I have yet to actually work on.
The quality is generally pretty good, though you're not going to be able to slap them together like a plastic kit, without a lot of filing and parts fitting. I'd really suggest them for advanced modelers only. I had one major problem in their XP-55 Ascender. The kit is very good, really, but the mold for the fuselage halves was on its last legs and the parts were covered with resin blobs and pits. Sadly I didn't notice right away (I rarely build anything right after I get it) and the kit is now OOP, so I can't get replacement parts.
I've been putting off building them 'cause they sure look like a lot of work. But a good modeler shouldn't have too much trouble.