You do a lot of climbing Bitteroot? I'd demo the giant first. My Trance 29er is very light on the front end. My only complaint with the bike. Hard to keep the front end on the ground climbing. Also have little to no steering control so it is bad on a tight technical climb. The geometry will change some with the smaller bike and would think this would improve. Great bike otherwise really like mine.
Yeah,
I like to climb so long as it leads to a descent! All the 29ers I have tried seemed like the front wants to wander on climbs.
My current bike is a Giant Reign 26er, and I don't have trouble keeping the front on the ground during climbs, even with pretty slack geometry and all that travel. My estimation would be the Trance 27.5 should be similar, but i will demo it first, as you suggested.
This thread makes me really curse the weather in Western MT right now!