Gah I wrote a nice long reply at work but the server timed out on me 🙁
What would you like to know about the Scalpel? I've had one for just under a year now (upgraded from a C'dale hardtail) and have ridden an Epic with the brain shock once before, though that was a little while ago, so can't really give a meaningful comparison head to head.
Quick synopsis of what I wrote in my chewed up post about the Scalpel;
It's a durable frame, don't worry at all about those carbon chainstays. That being said it IS an XC soft-tail frame, the rear suspension is there for rear wheel traction more than anything else. Don't expect to get big air on this thing. (This goes for the Epic too I guess, my friend who has one has blown the "Brain" thingy on the rear shock three times)
The rear suspension linkage is super easy to maintain. There's just one pair of pivot screws you take out and regrease every now and again. That's IT. The other moving parts use bushings which are quite durable, my frame is a few years old (and looks like it was abused by its past owner) and the original bushings are still fine.
I get a little bit of visible pedal bob, not enough to notice any real loss of pedalling energy though. But I have a crappy old Fox Float L shock.. the newer Fox shocks (04 and newer I think) with Propedal, or even the RP3 which most Scalpels these days come with, would be much much better in this regard.