I've heard people who own them or are selling them will tell you they are just as good as anything else. I personally wouldn't believe it. But if you are looking for something just to fish in its probably not a big deal.
If you are alking about using this for whitewater, then I'd say save your money and instead buy a set of used good quality tubes like aire, nrs, sotar, or maravias.
You should be able to pick up some bomber tubes for about the same price as the new Maxxons.
the aire tribs are probably much better quality than the maxon but they will be the first to admit they are nowhere near as good as the 10 year std product. there are some specials on these pages
AIRE | Rafts, Catarafts, Inflatable Kayaks Whitewater Rafting Accessories and Boats
I had a set of NRS tubes tear like paper on a rock on the shore. I only run Maravia and Aire now ...