If you can't ride the 29er on a trail, you won't be any better on a 27.5
You've got a real nice bike with the Talon; if go with the 27.5 size being better than 29er; that wheel size is just as obsolete as 29er's are; 27.5+ is where it's at for 2016 - as
#FrozenK says - Ride your bike