Go Test It is much more focussed on the browser automation and functional testing; BrowserCam is more about checking that the design looks right.
I didn't mean to imply that Go Test It is inferior to BrowserCam, I was actually curious what others throught. There may be a Mac / PC analogy here - both have almost the same features and so the primary differentiators are price, design focus, and product integration. If you aren't a Gomez customer, that last one isn't going to matter.
UPDATE: I'm getting my product names wrong. BrowserCam became a Gomez product called Reality View, and only provides screen shots. Selenium testing is done in a related product called Reality Check.