To be honest, their both good tubes.
The biggest thing that I noticed was, only the one bladder for the SFC, whereas the cumbie has two. I suppose the inflated seat/backrest could float the tube in case of a leak/accident.
SFC is easier to inflate, one valve, but u need the adapter. Forget the adapter, your screwed. U r also able to deflate the tube during hot weather with just a push of the finger.
No special adapter needed for the cumbie to be inflated. U can not deflate while tubing, well I would not advise it.
This may sound trite, but I like the zipper set-up better on the cumbie. One pull and both zippers zip. Also the zippers have a rubber cover over them to keep the water out when it rains.
The SFC has more pockets.....
SFC has the inflated seat/backrest. Spent 5 hours on the water, no but burn. My lower back is messed so the inflated seat was great.
SFC has no rigid apron, meaning a pipe crossing your legs. I'm still not sure if I will be able to adapt to the netted apron.
The cumbie hard apron allowed me to set lures down, no treble hooks in netting, have tools out. Be able to make repairs on my reel.
In the water, both tubes handle well. Can't see to much difference in either one.
Color, I prefer GREEN over the ORANGE, sorry TonyG. My Packers Hat went well with the cumbie.
Last would be the price. Naturally the cumbie is less $$, about 185 or sometimes less. I have not seen the SFC on sale, but then again I was not looking, because it was more than I wanted to spend at that time, over 400. The warranty on the SFC is longer, I think it said 5 years. If it has a flaw u will find it in the first year anyway, so warranties aren't a big thing with me. In reading all the papers, I noticed it was manufactured in Viet Nam, a place I visited back in 71.
Hope this helps someone in their decision, cumbie is a good tube, SFC is better if u have the extra bucks..........GT