I'm one of the tallest guys on the forum and I am not convinced a 29er is right for me, even after owning and riding a beast of a 29er for a month. 27.5 are nimble, accurate and can be every bit as forgiving. If I would have continued demo-ing bikes until I found one that made me say "I GOTTA have this" instead of doing an impulse buy, I would probably still be on 27.5. That said, I am not one to stand between a rider and her own impulse to "upgrade." If I may, let me just say, try them until one speaks to you.
EDIT: Depending on where you live, it can be very difficult to try every bike you want to try. How do you try Ibis, Transition, Yeti, Santa Cruz, Orbea, Revel, Guerilla Gravity, Intense, Speshy, Trek, Giant, Niner, Banshee, Kona, Mondraker, GT, Canfield, Foes, Cannondale, etc.? But if you can try several, you can get a good feel for the type of bike you like (geometry, travel, suspension, brakes, etc) which can then help you pick the model from the brand you are attracted to or have access to.