I've been using an EyeFi Pro, 8GB card for a year and a half. Works great. My current work flow is to download small jpegs to my Nexus7 pad, and keep RAW files on the card, which I download later via card reader to my work station computer. Trying to download RAW files via wifi is way too slow.
I use the pad for previewing, checking focus, and showing clients their pictures. They are always amazed how the images show up on the pad!
I did initially use the card to download images directly over my wifi network, to either my laptop or workstation, but found that to be clumsy, especially on location. When I got the pad a year ago, things just clicked much better.
This workflow is exactly why I'm glad that Phase One implemented wireless capture review the way they did on the Phase One IQ2
In any workflow where you shoot JPGs to one location and raw files to another you have a reconciliation issue. If they say they like an image (or rate it within whatever app you use) that must be later reconciled to the raw files.
And in any workflow where you shoot small JPGs to the review system you can't zoom into 100% of the full image.
And in any workflow where you send a full sized JPG or raw file the speed is poor-to-awful.
And in any workflow where wireless is "added" via some accessory, rather than built into the core of the camera there are hardware limitations like the antenna gain/range on an EyeFi card within a metal chassis.
In the P1 workflow you can rate the images on your iPad/iPhone/iPodTouch, and what you are rating is the raw file. No need to sync anything; you're only dealing with the master file. You can view the image at 100% since it renders the viewed section of the image on demand. And it's fast and has excellent range.
I've yet to find any other wireless tethering/review system I thought highly of.
In another few years I suspect all the pro cameras will have good wireless tethering/review options for commercial/ad shooting*. But right now Phase One is the only one that seems to have it really figured out.
Naturally I'm biased.
*Canon/Nikon both have wireless-pull options that editors in a media booth can use at a major sporting event (or similar) to pull files from their shooter(s) in near-real-time to get images posted online literally seconds after they happen. But this style wireless is at best mediocre when used in a fashion/portrait/product/landscape/architectural shoot.