Upgrading your 26 inch mountain bike to a 27.5 / 29 inch mountain bike is a personal question only you can answer. Buying the latest technology is tempting but you need to ask yourself – What problem am I trying to solve? There are many answers but be realistic. Remember mountain biking is about riding and having fun, shredding a new trail, being outside, etc.
I had to buy new tires because mine had holes in them. So instead of converting my bike to 27.5 I bought some wider tires that also ended up taller. I am very happy with my purchase. Check out the pictures.