Lwave is amazing but I've found it to have one of the most unusual interfaces I've ever encountered (certainly doesn't try to follow any of the usual Mac/Win interface conventions). Even just selecting and pushing/pulling polygons in the modeler requires all sorts of mouse and keyboard gymastics. Even though lwave has a ton of features (the particle system alone is amazing) I've struggled sometimes to have it produce output that looks as nice as what I get from Carrara (lwave doesn't seem to texture map as well as C and I get the best results in lwave using procedural shaders). I'm starting to think that lwave has a render engine that produces very "cold" output (great for space scenes and cars) that lacks the "warmth" of other renderers like Carrara or C4D. Don't know if there's a technical explanation for this (or even if I'm right in my assessment). Plus lwave seems to have a tough time with soft shadows (there's even a plug-in being sold to work around this). Everything in the lightwave world costs more, too (plug-ins, add-ons, etc.) The Sasquatch fur shader is very cool (a lite version comes with 7b). I think there's a 7b for sale over at eBay right now as well. I've even thought of selling my lwave 7 and waiting to see if Carrara 2 and amapi have enough features to keep me from lusting after c4d (which does seem to be a bit of a bother when it comes to animation).

Lwave has subdivision surfaces for modeling (basically you make a chunky rectangular blob by pushing your mesh around and it makes it smooth and organic looking when you hit the TAB key!) but I find that the hypernurbs in C4D yields nicer-looking results (fewer artifacts, less smearing, and generally a smoother look). But if you're into subd supposedly Amapi has several different smoothing options and thus in some ways could be better than lwave or c4d.

Personally I'm looking forward to Carrara2 (with a few more features and its nice warm output C2 should be able to hold its little head up high).

If you're intent on leaving Carrara behind also take a look at Cinema 4D Art (v6 without the animation) and take a look at:
http://www.maxon-computer.com/deepshade/

Hope this hasn't been off-topic (or downright rude to Carrara) but as a recent Lightwave purchaser (who still loves C but is also lusting after c4d behind C's back) I thought I'd share my experience. Also, I'm a relative newbie so take everything I say with a grain of salt. Sometimes I've noticed that the beauty of high-end programs doesn't always become apparent until you've spent lots of time with them (or have to do a job on deadline for a client).