I'm new to mountain biking, so I have limited experience so far. However, I went from a hardtail to a full suspension this summer. I did a lot of research before buying and also considered a 29er as an alternative. I decided against that because of my size. I'm just barely 5'4, petite in build, and need to feel in control of the bike. A 26 inch full suspension gives me plenty of height, and a 29er was more than a tad too high for my comfort level.

There is a huge difference in feel with the fs vs hardtail. I have the Juliana RXC (Santa Cruz). This bike is much lighter than my hardtail, and very fast. She floats on trails and glides over glass and rocks. The Juliana actually feels "harder" on regular paths than on mb terrain. As soon as I hit terrain she seems to light up and start to fly.