I’ve used it and I consider it an excellent complement to any PE routine.
I don’t think it’s possible to gain just from it, if ever is possible to gain from any mechanical tool (just this afternoon I noticed they now make this claim on PeniMaster + PeniMaster PRO - manufacturer’s official site , but I wouldn’t believe).
This means, if you do exercise to gain in length and girth, then wearing the Xleeve for as many hours as possible in the rest of the day will help cementing the gains and (probably) supporting faster gains.
It’s very easy, actually. The pressure it provides is minimal, so minimal it’s impossible to consider it an extender.
But, it works great in gently keeping the penis stretched at all times (sleep include), and that’s good.