The DVX100 records rather compressed video as does almost every DV camera. You can capture the video via firewire without any further compression, in fact that's the only way you can capture it.
What you get is a bit copy of what's on the tape.
Bob.
All DV cameras record video compressed the exact same way. And none of them can export uncompressed through the firewire. You get DV from the firewire. DV is a compression system.
Firewire is a data transport system, it can transfer any type of data that the host and recipient decide to transfer (which is why it can work for HDV and DVCPRO-HD as well as DV). However, DV cameras only support transferring DV-compressed data through the firewire.