I demo'd the Evil Wreckoning. 29" 161mm rear travel. I was bored. The bike made everything too easy. I've been riding 29er hardtails since the late 90's and appreciate what they do for my ride but to have fun on them you need to get a geometry that allows really short chainstays. If you are into choosing a straight line through any tech section and going over everything like it isn't there then long travel 29 is the way to go. 27.5 is more fun to ride imo. The bike accelerates quickly and easily, feels more lively and is better in the tight technical terrain that I prefer. For shuttling whistler runs or flow trails the 29 is definitely a faster and more stable bike.
The one thing I will say that blew my mind was that the Wreckoning didn't even feel good until you were going over 20k/h. The faster you go the more stable it felt. It feels more like a motorcycle that you have to lean to turn rather than turning the handlebars - incredible ride! Just not the ride I'm looking for. BTW, I'm 6'2" and 220lbs and these were my impressions, I certainly would not recommend a long travel 29er for people 5'7" and under.