Buy a camera body with built in wifi?
Nikon and Canon do specific wifi adaptors which plug into your micro usb slot.
Can't help you with real world review. The issues from reviews with both cards is that 1. They eat your camera batteries and 2. File transfer is 10 to 20 seconds per picture (lowish quality) so you not sure whether that would be quick enough of not?
Like they do on America's top model you mean? Yeah would be nice but I suspect you pay £800 for the proper thing from Canon compared to £40 for a reason?
I'd try and hire one in for the event. That way it should cost you much and if it's pretty instant and works well, you can look at buying one for the long term?
Looks like £30 a day/£120 a week gets you one on hire. and they can be bought for £429 now. That 150Mb/s transfer speed is appealing.