I recently had a flat tire with the airless extensions. Inside tire on my Class C. It was not the fault of the extensions, but the tire store that installed them too tight, and my fault for not checking behind them.
The problem with the ones I had (bought from Camping World) was they were installed too tight. There is a fine line between too tight and too loose, they have to be installed correctly every time. Too tight and you are constantly losing air pressure, too loose and you cannot add air or even check your pressure.
Bottom line is, if you go with airless, make sure you check behind whoever installs them to make sure they are right. Good luck.
