Personally I love it. Yeah its buggy but its very useful. On the first release my big problem was having to maximize the window on every app you opened, but now there is an option to maximize on the startup of the app.
I use it to watch Netflix, Twitch, on board video etc. while browsing the web, or just to keep their audio playing in the background while I have another app maximized.
If you use the iPad vertically you can get a very large readable web window on the bottom and have all black bars of widescreen video off the screen and covered up by the web. Very effective use of the screen space.
The option I'd really like added is the ability to pin an app on top.
I leave it off by default because it does cause occasional crashes and needless clutter in closing things if you don't need to multi-task, but it takes all of 10 seconds to respring it on/off so thats no big deal.