Greg,
I own a few of the current crop of cameras:
Lumenera LU075M
PGR Dragonfly Express
PGR Dragonfly2
DMK21AF04.AS
Comparing firewire and USB cameras is a tricky subject, you have to be careful that you really understand the differences. Firewire cameras are cross-platform and will run when connected to Windows, Linux or Mac, normally with any firewire video program because the video is part of the firewire specification.
USB cameras require a specific driver wherever you want to use it because there is no usb video spec and so every camera does it differently. eg if you have a camera with a Windows driver then it probably won't work anywhere else, and you'll be relying on the vendor to keep releasing new drivers for new versions of windows.
Because I use Linux for my video capture and scope control I have no real choice but to use firewire. I have one generic video capture program called coriander that understands all my firewire cameras, with no vendor-specific driver needed.
Firewire also has a lower cpu usage since the firewire driver chip can transfer the video itself, whereas usb needs the cpu to assist in receiving and saving the images.
My current favourite cameras are the PGR Dragonfly2 and Dragonfly Express, but I'll be upgrading to this camera as soon as it's available:
http://www.ptgrey.com/products/grass..._datasheet.pdf
The specs on this camera are wonderful, and the new kodak ccd's are very low noise. The 14 bit ccd will be an improvement over my current 12 bit ccd in the Dragonfly2.
The only downside to firewire cameras is if you're using Windows - I'm not sure there's a good firewire capture program out there for Windows users - maybe there is, if anyone knows of one they can post about it? Under Linux there's coriander which is one of the best capture apps anywhere.
PGR are also releasing a new software dev kit (SDK) which will be cross-platform, so capture apps written for Linux will run on Windows and vice versa. When I get my hands on that I may start writing or porting my linux app over to Windows, but there's no word on when this will be released.
cheers, Bird