* GURPS encourages you to manage your rules as you see fit. You can either run GURPS using the Lite rules (and even play with those to make things even easier), or you can go full-throttle rules madness and buy every supplement you want and incorporate every variable/skill/advantage/power you feel like. The players can either be all over the variables and get as crunch-geeky as they want, or the GM can keep it all "under the hood" and just ask for rolls and do the tweaky bits themselves. This way the game can be played as rules-intense or as rules-casual as you like.
GURPS is one of those systems that just begs for houserules, and lots of 'em! Even if you're using an official setting, you'll want to tailor it to your play style and interests. Be sure to check out the comments for transforming GURPS for more "traditional" fantasy play.
I enjoy the system much more than I get to play it, and it's usually my go-to system for sci-fi play. And being an Austinite, I gotta support the local RPG pros. ;)