I'm seriously in love with this bike. I came from riding a Niner RIP 9, so I had pretty high standards, but this bike just blows everything out of the water I've ever ridden. It's incredibly responsive and stiff- it just goes the second you push the pedals down, and you feel like everything you put into it while climbing gets transferred so well. It seriously flies up hills.
The slightly slacker head angle is something I wasn't sure how I'd like, but it makes for super fun descents. I feel very confident tackling all sorts of terrain on this thing. I'm running a 140mm fork, which I think just makes the bike all the more fun.
For me (I'm 5'8"), the shorter top tube and chain stays make the bike super playful, but the slacker head angle also gives the bike a ton of stability and confidence when going down. I'm riding a size medium, and it fits me so much better than the Niner Rip 9 medium, which just always felt a tad too large.
Can't say enough good things about this bike. I wish I could ride it every day for years on end. Way to go, Yeti!