The GoPro HD has a firmware update that allows for the camera to shoot up-side down. As mentioned, the is a LCD screen available for the Go Pro as well. It is called the LCD BacPac, comes with a new waterproof housing, and retailed for around $80.
I just bought a Go Pro because of the multiple mounting options. I also have a Vio POV1, I like it but the mounting options are a little limited because of the camera head being tethered to the remote recorder.
One thing to consider is whether or not you plan on editing the video on your computer. Does your computer/software possess the performance to edit in HD? I am a PC user, and experimenting with software that can handle the HD video. My computer is only a couple of years old, and the software I used to edit the Vio video won't handle the HD video. From what I can tell you will need at least a 2.4 GHz multiple core processor, 4 gig of RAM, and a decent video card.