Right, full disclosure right up front... I worked with an online retailer who specialised in adventure camcorders and I'm now with the importers of one of the brands you mentioned. That said...
Here's my take on the cameras you looked at:
If you're worried about the budget, go for a GoPro White Edition. It's cheaper than the entry level Drift HD and is the better buy. You'll get a full HD camcorder which shoots 5Mp stills as well as a mount for your helmet. It's a really solid buy and you'd be saving around R250.00
If you're looking higher up the food chain things become a little less clear.
GoPro have the Silver Edition, which is basically the Hero2, repackaged in a new chassis with built-in WiFi. Really good camera... That is, unless you want a remote control. Those puppies will set you back R1300,00 which puts you right in Black Edition territory and the remote comes free with the Black Edition. Between the Silver and the Black at virtually the same price, there is no choose really... Black Edition wins every time. There are the new Hero3+ Silver and Black Editions , but for me at least, the logic stays the same... Buying a remote control, buy the Black Edition.
The Silver Edition gives you an 11Mp sensor and a side mount for your helmet and a few more options than the White Edition for setting frame rates at 720/1080p. The Black Edition gives you the same mounts as the Silver, a 12Mp sensor and, IMO, it's real party trick, just about every frame rate you can think of in 720/1080 and it also shoots in 4K. If you're a serious video editor, the GoPro Black Edition cameras are the ones to look at. Seriously.
The Drift sits somewhere in-between the Silver and Black Editions... It's easier to use, mainly because of the screen and with video settings, its as good as the Silver Edition but falls short of the Black Edition. It has it's own party tricks 'tho. That built-in screen for one (R1300,00 for a screen on a GoPro), a rotatable lens and the one that I find most important, a really long battery life.
YouTube has a couple of side-by-side comparisons but that might make it more confusing. For every video where the GoPro wins there's a video where the Drift video looks better... Bottom line. Decide what's most important for you... The look of the cameras, the video editing options, a screen, battery life... Buy the one that fits the bill best and, whichever choice you make won't be the wrong one.
PS. The Contour, 'tho not huge in SA was the second best selling camera in the States. Problem is the "was" part. Repairs and accessories will become a problem as the local agents run short of stock. If you go that way you'll need to keep that in mind. Also, there's the Sony, which really compares with a White Edition GoPro but it's pricey and doesn't have a wide range of mounts and the mounts are expensive... Just saying.