Alternative capture?
 

For whatever reason, capturing tapes in my HV20 via firewire on my mac using FCP results in a ton of dropped frames. Might I have better luck using a third party utility to capture the m2t stream off the tape, and if so, what utility would that be?

Dropped frames can be caused by several factors, mostly hardware related not the application. If you have more than one FW device hooked up at the same time; if the tape-head isn't clean; if the transport isn't stable; if you have automatic preferences turned-on in the OS; if you're capturing to a single internal HDD rather than a second internal (or external on a laptop)...the list goes on.

Try doing a search on capture presets and the best environment for the hardware setup; there may also be additional tips in the Canon forum for this specific issue.