I also use the Quantum Radio Slaves and they work great with my Canon 20D. One 'problem' with the Radio Slave system is you need a synch cord to connect the camera to the transmitter, whereas the Pocket Wizard attaches directly to the hot shoe, BUT it sticks up in the air a bunch. As clutzy as I am I would be afraid that I would bump it on something and break the hot shoe off of the camera, and besides I already have the Radio Slave system so I decided to make it work of my Canon. To make the Radio Slave transmitter fit, I took a little plastic hot shoe adaptor that I've had for years and attached the transmitter to it. It only sticks up about an inch or so above the camera. But after using it for several sessions I found the cord tended to get unplugged out of the PC socket in the camera quite easily. So I bent up a short piece of flat steel into an "L" shape, drilled a 1/4 inch hole in it and attached it to the camera using the tripod socket. The other end fits snugly up against the synch cord keeping it firmly attached to the camera. I basically have nothing in it except a little time.
Benji