Thanks, all for your great responses!
I hadn't even considered the lack of Firewire port. It sounds like I SHOULD keep the HV20 for now too. (The FS-4 belongs to work. But I have free access to it.) But Stan's response was encouraging on AVCHD machine specs. So another question: If I am using AspectHD in Premiere Pro CS3, when I import the files into Premiere, will Cineform convert them to something usable/playable on the timeline? On a related note, should I upgrade to ProspectHD to get the full benefit of 1920x1080?