Hi Tim, unless he got them on an educational discount, Becco has laid out quite a bit of cash for tools. Cinema 4D Core is about $900, BodyPaint is around $800 and the Maxwell rendering engine is $1000. C6 bought new is $550 (my upgrade from C5-C6 was $149). Amapi is $749 list, but if you own any other e-frontier product it's $149 (go figure).
I use the toolset I have because I already have the licenses, they work well and it costs zip to upgrade whenever an update comes out. Basically, I'm into cheap

. My next major investment is in hardware -- time to go quad core and 8 GB memory with a 64-bit OS.
Amapi may not have another release, although it appears that 8.0 is finished and ready. But it really doesn't matter. I'm less concerned about using a particular tool than I am about developing geometry in an interchangable file format. I figure if I build a parts library in OBJ format, I can move it into anything. Tools change all the time -- you don't want to have to redo good work though. It's hard enough doing this stuff once. Someday I may abandon Carrara and Amapi altogether, but so far I just don't see a good reason to do it now.
Nurbs. I think you're either a nurbs guy or a poly guy. I have drafting/CAD experience and nurbs make total sense to me. My attempts at vertex pushing often wind up looking like wadded-up tinfoil

. Nurbs are utterly precise. They're lousy for organic modeling, but for machined parts they're ideal.
More is coming -- those shots I posted earlier are quick renders in Amapi. The next batch is going to be out of C6. I'm working on detailing the parts that hang off the cylinder, and the cam tube and rocker boxes. It's alot of stuff