Yes, it's worth it.
I paid $99 for Rapture, which was a great deal at the time.
The full version has a lot more presets, plus it is more controllable, and versatile, than the LE version.
I like playing Rapture with a controller, because it allows you to work the patches.
Here are two examples:
http://soundclick.com/share.cfm?id=6300120 The drums in this one are from Session Drummer2 (also a worthwhile download at $10), but the rest is one patch in Rapture, with a little keyboard manipulation.
http://soundclick.com/share.cfm?id=6170515 This one is a straight patch, again with some keyboard tickling.
Both of these use unaltered presets.
If you want to dig a little deeper, you have plenty of room, and I have heard some incredible stuff that people have done with it.
At $49, this qualifies as a no-brainer.