I had one. Now that I sold it, I can be totally honest.
The front end was the stiffest I've felt. The feeling between the feet, bars, and front end was unparalleled with a fox 36 and 20mm axle.
The frame is pretty light. It's like 6.5lb but that puts it competitive with almost everything else.
The cable routing is really well done. You just shove the housing in and it comes out the other side. The brake is external.
The geometry is awesome. Room to move but not kona stretched out. Worked well for me on the east coast. Chainstays are short but not excessive. Head angle is slack but not excessive. etc.
Suspension is pretty good. I like having lots of anti-squat for agressive climbing and it was there in spades.
I hated the seat angle. I found a few tricks to make it work for me, like running my thomson backwards (approved by thomson, but my post has issues and I can't say it is/is not from that), and running a fizik THAR saddle that has extended seat rails so it can be jammed forward. I was able to get my seating position with these tricks. On other bikes it's no problem.
I felt like the back end was flexy. It's hard to compare directly because I don't own 18 bikes, but I felt like the rear end would wander and it was hard to "feel" what was going on back there.
I hate the shock. I'm biased against RS products because they are all terrible, but the monarch didn't have enough support in "open" and too much in "trail" so I was always hunting for good feel. Options to replace are limited- avalanche tuning or a Fox float. Nothing with adjustable compression.
The build quality was, in a word, "fuckin terrible". That's two words, sorry. I couldn't backpedal in my three largest gears, or the chain would drop. I can do that in all but the very largest gear on my BMC with virtually the same drivetrain. The frame was shipped with a shimano axle that would only engage two threads in the nut if the nut was reversed. I eventually lost the nut and bought a new axle direct from evil. This one would engage three threads. I think the frame might work with a longer SRAM axle or even a boost axle, but not what they shipped and designed. The same axle and hub setup works with zero flaws in my BMC frame.
I think the suspension would work well with a larger front ring (I ran a 30t I think), so I'd probably prefer a 32 or 34. I would immediately ship the shock to avalanche or score a fox off ebay for $275 off ebay unless you are a lighter rider or don't want a lot of compression support.
I probably wouldn't have sold my frame except I scored the BMC for $480 off ebay, and I've always wanted one. The BMC gets me a piggyback/adjustable shock, added stiffness, the same geometry (with a more upright seat angle) and slightly improved suspension, so I'm pretty happy with the move. I do hate the rattle of the cables inside the frame though.
Let me know if you have any other questions. I did enjoy the frame but am happy to have moved on.
There's a photo somewhere, maybe in the "what's your ride" thread. Originally I had an Xfusion, which had like 15mm of layback, reversed, and caught plenty of flack for it. I sprung for the thomson because the xfusion sucked.
I think it's pretty telling that the main upgrades to the V1 were a boost rear end (for teh stiffness), a trunion shock (for piggybacks), a shaved FD hanger, and longer reach. I don't think they're bad bikes, but if you're looking for greatness, I think there are clear issues that the wreckoning and calling help fix.