I have a '12 Reign 2 that I bought as a re-entry to mountain biking back in 2012 and I have to say I am really happy with it as a platform. The stock components on the Reign were not what I have ended up with, but it allowed me to learn what I wanted from a mountain bike and upgrade in steps. In fact, I think the only thing left stock on it is the frame, LOL.
The geometry has proven to be somewhat future proof as well. 67 degrees was considered pretty slack a few years ago, now is fairly standard for a trail bike. Would I change a few geometries to suit me better as a rider today?? Sure, but only a little and had I known myself better as the rider I would become I would have gotten a Small instead of a Medium and it would have taken care of half of the geometry changes I would make.
As for the need for 27.5" wheels, I'm pretty certain you could make it work if you wanted to with this frame as well, depending on the tire choice. I chose to go Chris King and Spank 26" Subrosas with a Maxxis Ardent/HR2 2.4 combo. The diameter is just a smidge smaller than a 27.5 with a 2.2 tire and I still have room in the chainstays if you wanted more of a "+" size tire.
All in all, an excellent choice in my opinion.