My $.02
[You must be registered and logged in to see this link.] - Has to have a ruggedized bottom. Rubberized or PVC bottom are non-negotiable. I launch and land in some rough places, and Cordura or ballistic nylon bottoms are non-starters. I'll kill them. I have.
[You must be registered and logged in to see this link.] - Redundant Flotation. My beloved Wood River tube inflated the V pontoons, and also had an inflatable back rest. My current Fat Cat has a single inflation for the V pontoons but has a floating seat and back. Ideally, there will be two inflation points for the V pontoons (several have this now) so you can loose a 'toon and still limp back to shore. A round belly boat without an inflatable back or floating seat is dangerous to me.
[You must be registered and logged in to see this link.] - Storage on the arms. Storage behind me doesn't do me any good - I toss leaders and other stuff I 'might' need back there. Storage on the arms (above the 'toons) is where the stuff goes that I WILL need. And I bring a lot of stuff.
[You must be registered and logged in to see this link.] - Comfort. I will be in the saddle for hours. The seat can't be too long (some are) whereby they put undue pressure on the back of my legs as I kick and kick. I sit up nearly 90 degrees - so I like a tight back and clearance for my legs. My Fat Cat has both.
[You must be registered and logged in to see this link.] - Capacity. I'm not a big guy (173#) so any modern tube will float me comfortably. If you're a big guy, you don't want to Jimmy Dean into the seat or sit too low in the saddle. Check capacity. All tubes have ratings. Remember, it has to float you AND your gear.
That's my short list. I don't care about weight, or rod holders or after-market accessories. I make my own stuff and I'm pretty strong. Getting my tube to the water fully loaded is not a problem. I'm not packing it in.... there are lightweight tubes for that purpose. For my every week, launch over the rocks, bounce off the docks and the trees kinda fishing I do - the 5 above are what I look for.
- Ken