I have the proclip for Bionic, got it yesterday. The bionic does not know it is docked. In the D1 proclip mount, there was a magnet option. Bionic does not seem to sense the dock with a magnet anyway. That is okay, as I hate the car dock app, so I just spent the day moving everything to launcher pro, which will rotate the home screens, and as an added bonus I get 2 more home screens. I was trying to avoid launcher pro because of the lag on the D1, but all this memory on the Bionic solves that! So far, so good.
As for paying more for proclip, yeah it is expensive. But I like the dash mount above the air vent and don't need to worry about the bionic coming loose, flying when I hit the brakes (hey, I'm a jersey driver), or spilling my drink on it.