
I've not run into any transfer issues using an Eye-Fi card on any of my cameras. And even if it did take more than a few seconds to transfer a photo, so what? Is this what we've become now, waiting more than 5-7 seconds for something to happen is too long? How long does it take to transfer and process the photos from your memory stick? With wifi, it's all done automatically while you do other things.
I agree, shooting events, it makes everything flow faster for me, plus having the ability to upload to my website the JPEG's as proofs puts me ahead of the curve for those that want to buy off my site instead of buying a print on-site.