Santa Cruz Tallboy LC Carbon? First mountain bike?

Trying here to decide on the first mountain bike for me.  At the moment the leading contender is the Santa Cruz Tallboy LT Carbon.  I guess I should call it that, although I want to call it an "LTC" but that name seems so "2014" by now.  Oh wait, we're still in 2014 but with the new 2015 models being released it looks like we're on to the new naming nomenclature.  The Specialized Enduro S-Works was more fun on the downhill but didn't climb nearly as well.  I also tried others like the Specialized Camber but while that climbed pretty well I had no control going downhill.  Any thoughts on if I'm making the right decision?

Mountain bike saddle question...

So what makes a mountain bike saddle any different from a road bike?  I know a road bike saddle is supposed to be comfortable, stiff, lightweight, etc. and I love my Fizik saddle.  But I see there are tons of mountain bike saddles out there and they don't seem to overlap with saddles for roadies.  I get that you might not care as much about shaving grams on an all-mountain or downhill bike, but should the padding come from the shorts and the "give" come from the MTB suspension?