there is a lot of different brands out there the one i worked with is uponor and i have to say its pretty good as plumbing option. what you want to use it for? its semi ridgid so for something like sump return or drain might not be the best since it will be sort all over the place
I have it in my house. It was built about 3 years ago. Love the stuff. The pipe is cheap and easy to use. The fittings can be expensive. Most hardware stores carry brass. However if you go to a plumbing supply shop you can get plastic fittings for about 1/4 the price or less.
Next the crimper used for PEX is expensive. But once you have that it's the only tool you'll need.
Note, the larger diameter pipes do not flex all that much but you can make full bends provided the radius of the bend is big enough.