I've got the JVC digital cam with firewire and I've had reasonable success with transfers.
Depending on the software you're using, try adjusting the capture settings in your software.
You do have to be careful that the settings you choose conform to the standard required by the output format.
SVCD & VCD both have min/max limitations in the settings.
There are some good tutorials here and elsewhere regarding settings for optimal capturing.
I've experimented to get what I deem as being a good mix between quality & file size.
Most of my home movies I've done as plain old VCD.
It's not perfect but it's no worse than VHS, so I'm happy.
My advice to try capturing snippets of video at different settings to see what you end up with. To get the same quality as you DV, you'll have to capture in either DV mode and burn it as DVD (with some of the ULEAD progs, you can burn about 15 mins of DVD quality stuff onto a CD-R).
I'm not an expert, I'm sure there are others who are around here, but I hope this offers some help.
Have fun....