Had an offer from friend in LBS. He's not gonna ride nearly as much and really likes me Trek. He says he'd do a straight swap from my Trek 5500 frameset.

I'm very tempted, however what's the Scott's lifespan like? This one has barely been ridden and is in perfect condition.

Should I go for it?

heh, HELL YES

have you acutally seen the bike and the condition its in? if so, i would say go for it, if offer is still good.