I went through this same deliberative process a few months ago. After getting over the fact that I didn't need a mountain bike for the bike trails - I headed to Mike's Bikes in midtown Sac and ended up with a Specialized Globe - here:
http://mikesbikes.co...els-57476-1.htmI'm a tall guy - just under 6'5" - and the XL worked out really well for me. The seat is quite comfortable. Note that, in addition to the springs on the seat - the seat post has a shock/piston, as well as shocks on the front forks. Pretty light as well.
I've been riding it quite a bit for the past couple of months and really have no complaints.
I also debated about the used bike on craigslist - but really didn't want to deal with someone else's potential problems - so I just went new.
Your mileage may vary . . .