My main thought is that these are 2 totally different bikes. One is a 27.5 and the other is a 29'er. When you go downhill and make turns, which feels more comfortable. Even though the Trek is not out yet, you really should demo a 27.5 vs. a 29er going uphills and downhills, not in a flat parking lot. They should feel different.

If you still cannot decide and both of them "feel the same" to you, then I would pick based on color.