I just purchased the V700M.
Used to own a Sanyo HD1000 (pistol grip type) and a Polarizing Filter too.
I'm not an expert in this videography thing. Mainly using it for family outings/gatherings.
After I installed the Polarizing Filter for my previous HD1000 camcorder, I found that it will automatically adjust the brightness. For example, if I want to have a "bluer" sky I will turned the filter to a certain angle. But after a few seconds, the sky colour becomes lighter. It seems like my camcorder automatically adjust the brightness. All my settings are in Auto because I am not quite familiar with manual settings.
For my new V700M, I don't think I will be using any Polarizing Filter. But would you recommend a normal UV Filter (Multi coated type) instead? There are some quite reasonably priced filters I found on ebay. But the thing is, will it make a difference in the video quality if I use a UV Filter?