Many of my clients like to be able to see the results from a shoot real time, which is great by me because I can get real time feedback on the shoot. I used to have to take my laptop and a long 25 foot USB cord to hook my camera to the laptop. Between the cord and the laptop it was kind of clumsy. I like to move around on a shoot and being tethered doesn't help. I often shoot outside, and here again, the cord and laptop just got in the way and the laptop was hard to see in bright light without some kind of cover.
I read an article about an iPad app called ShutterSnitch that allowed a photographer to easily acquire images from his/her camera over WiFi. Many photographers use the Eye-Fi card, but it only comes in SD format and my Nikon D4 doesn't support that. You could use an SD to CF card adapter but I read about a lot of problems with weak signals and slow transmission. Then there was the Nikon WT-5A Wireless Transmitter which is designed for use with the Nikon D4 D-SLR camera. At $553 dollars at B&H it was a major investment vs. a $69 SD Eye-Fi card. As I always tell my kids, when you GO CHEAP you PAY MORE.
How many times have you bought something that was cheap and supposedly just as good as the best solution, only to have to deal with all the frustration and lost time, and at the end of the day you finally end up buying the best solution anyway. And when I am with a client I don't want to be fumbling with unreliable equipment.
The WT-5A fits like a glove on my Nikon D4. It was fairly easy to configure, and the connection to my iPad was fast and reliable. The ShutterSnitch app is very intuitive. It acquires the photos quickly, it allows you to rate and sort the files quickly. Customers love to flick through all the photos and rate them real time.
On a portrait shoot I use to put the proofs from the shoot on my website and have my client pick their favorites when they got back to their office. Because the iPad is so easy to use and setup, I find myself using it on portrait shoots and I allow my client to pick their favorites before they leave and I can go right to retouching without the intermediate step of putting the proofs online. This saves time, disk space, and my clients get their images faster. The $553 for the Nikon WT-5A was money well spent!