I can't tell you right now but I have a VX2100 and I have a V1U is in transit. So I should be able to tell you something soon. I did shoot on one occasion with both but it was under low light conditions (like many weddings). Under those conditions, the VX2100 was far superior and the only way I could get them to intercut was to "detune" the footage from the VX2100. But the shooter with the V1U had just gotten his camcorder and he may not have had it optimized quite as good as it could be with more knowledge and experience.

it would be best if you can get the cameras close BEFORE you shoot.
for that a WAVEFORM monitor and VECTORSCOPE would be best BUT barring that get them both up on a TV (the same one) and use the color bars in the camera. Use the Custom Presets or whatever else you have on the cameras to get them as close as possible. Remember also that viewing thru the LCDs will not neccessarily give you accurate looks at color and exposure so the first thing you need to do is set the LCDs to the bars so they are both relatively the same as to brightness. You can set the color level of the LCD in the menu, at least you can on the 170 and I think you can on the others.
It sounds like a lot of work but it is the only way to get the 2 cameras close otherwise your could spend alot of time in post trying to geth them to match and they still might not. Do as much work before the shoot so you spend less time and have a better chance of matching them later.
Don

I have the Sony PD170 & Z1
What I do is get them looking the same at home through the LCD screen. I have a board that has a lot of color and writing on It and I know If this is looking good through the LCD It's about right.
Then do a test record and put it through your NLE and do a quick render, 30sec Is all you need.
Remember when you go out shooting to always white balance with the same white card with both cameras pointing at It ( you know this anyway ) this way you should be close. I allways white balance when the lighting changes.

Good luck
Simon