Practical uses? Well, it's a window manager, like any other. It gives you borders on your windows so that you can move and close them
On a less I'm-being-a-smartass-note, it's really pretty, if you get a good theme for it (I'm enjoying
arietta). It's incredibly customizable, and you can do
many nifty things with it. My main problem is most people's ideas of themes are a) bright white and b) square, or else are c) ports of other wm's themes, which to my mind sort of violates the whole idea of themeable...be inventive, for pity's sake.
It's customizability makes it fairly easy to modify, if you want to take the time to learn its ins and outs. Sadly there's no nice little tool which says "make my menu backgrounds X color, and my titlebar should be THIS image in THAT location on a window", so it involves a lot of "grab a theme, install it, and start mucking with files".
So yeah, it's pretty, it does what it's supposed to, it's customizable....it's neat to try, and I'd highly recommend it if you've a package-managed system which will take care of the quasi-complicated and depdancy-ridden install for you.
HTH!