Can anyone tell me the difference between Uponor and Sharkbite pex a tubing quality? The uponor is more than double the price and do want to use it if it is better.

I can't tell you specifics in the actual tubing in terms of materials or manufacturing processes.

I will comment in two other aspects that may be relevant.

First is the warranty. uponor and SB both have a 25 year warranty on the tubing as long as you use their fittings. If you use non uponor fittings on uponor tubing or non SB PEX fittings on SB tubing then it's 10 years only. So when considering which PEX I suggest taking that into account in pricing out the whole system if warranty is important to you.

Second is I suggest staying away from uponor blue and red PEX A tubing and get the white only. The colors are added at the end and there is a class action law suit against uponor as it seems the coloring process might have weakened the tubing resulting in more leaks and bursts. The white tubing has no such issue.

Uponor Pex piping is be signed to stretch and then return to its original size. I have used all different types and brands of pex through the years I feel that uponor pipe is probably the best quality pipe on the market. But that being said PEX tubing from any reputable manufacturer will be an excellent product. In my plumbing company we use Zurn pex pipe and fittings and have for quite some time and have very very few issues.