I have one for the 10D, it's as good as the Canon one but less then half the price.
Its just a ****ty shutter release not worth arguing over, if you think about, both are made of really cheap materials that don't cost anything to build. I bet the Canon one costs in the area of about a buck, probably alot cheaper. Eitherway, you are getting the same simple wire with a button hooked to it encased in cheap plastic.
IMHO, there are things that are worth fussing over and things that are not. Looking at a body or lens where lots of research and skill is required to build it, it matters, but not for somthing you could make yourself after a visit to Home Depot. Put it this way, go buy a Canon one if you want, but also know you coulda also got a grey card or a small uv in that deal.