Videography: where to draw the line?

My videographer/photogher team is offering me a great deal for a documentary-style video. It would include 2 cameras for the whole day (prep through end of ceremony), along with interviews. I saw a couple samples and loved the way they turned out, but I'm concerned this will be too intrusive. I don't want guests to feel like they're being put on the spot, and I'm people will feel self-conscious if they feel they're always being filmed. The cameras wouldn't bother me so much personally, though.

Has anyone been a part of a wedding where you self annoyed/self-conscious because of the cameras? How much video interaction is too much? Just wanted some opinions! Thanks!