I was all in on a 29er for my first mountain bike, but my LBS talked me down and into a 27.5 with plus sized tires. The biggest reason is the 27.5 is a little easier to handle for a beginner. However, going with the plus sized tires I get about the same outside diameter. Therefore, I get about the same ground clearance. Also, since the bike was built for 27.5+ tires, it can also accommodate 29er's if I ever feel the need to make that jump.
My 2 cents.
