Cumberlands are great tubes, not too pricey and holds its own against the higher end ones.
I own a caddis pro 2000:
Probably the lowest sitting vstyle tube there is. It pretty much means you are sitting a little below water level. Super light and packable.
Fat cat and odc 420:
Both great heavy duty tubes. Noticeably heavier than the c0umberland, these are tanks of the tube world. You sit pretty high and these generally hold a decent amount of weight as well. Draw back is they are heavy, sit higher in the water meaning you catch wind more. The lack of a "spreader bar" means if you under inflate your tube, you may have a taco effect going. The fish cat has an inflatable seat/backrest option and if you pop a bladder, the foam seating is more than boyant enough to act as an swim assist device to keep you afloat.
Caddis navigator:
Pontoon style tube...still sits in water, drag sucks and the smaller valve for the back rest is strange to say the least. but, rolls up small and very packable