I've fished out of both tube and pontoons. It all depends on what type of fishing your wanting to do. If your looking at primarily fishing waters close to home and want to get into the water withing minutes, or decide to take short hikes to back country lakes, then the float tube is the way to go.
If your looking at putting in at some of the larger lakes, or float small rivers, then choose the pontoon. I currently have a Big Bucks float tupe and a Skeeter as well. If you can afford to kick in an extra hundred bucks than go with the pontoon. The prices on these units have come way down in the last couple of years, and you can now get them with trolling motor plates and additional bells and whistles for under three hundred bucks. Think ahead, and decide whether you want to add a trolling motor and battery to cover more water and then decide. Float tube or pontoon, either one is a good choice.
Pete