So recently I've been using X-Plane a lot more recently, but have not really delved into the weather depiction side of things. The default clouds aren't really that good, so I've been looking into some weather plugins. 

I currently use ASXP + XVision, and it looks okay enough, though what do people think about the all the other plugins? (XEnviro, SkyMaxx Pro, UWXP, FSGRW)

From what I heard XEnviro was pretty bad with performance, usually halving the framerate and half the times it produces beautiful clouds while the other half it produces streaky blurry clouds. And the $69 price tag is very intimidating.

SkyMaxx Pro i honestly wasn't that impressed by the screenshots, I don't know if they're underselling it or what but it doesn't look any better than the default clouds.

And I have no idea what to expect with UWXP.

From my experience with FSGRW from FSX/ESP, it was okay but most of the time it was meh and ActiveSky eventually overshadowed it. 

I also don't know if it's futile paying for these software, is it better to just wait out for Laminar to implement their own volumetric cloud system?

You're served with asxp, at least until xp12 get's released an as far as weather injection goes.

Even better - you're already enhancing the visuals of a great ( maybe the best all summed up... ) weather injector with XVision...