The use of wireless upload to on-line sites is nothing new.
By now you would have thought that Nikon would have it perfected, but as usual they are late to the game and fell a bit short with the WT-4.
For Studio work it's little more than average in performance.
Transfer rate is almost laughable when compared to what is on the market for wireless transfer.
It's very stable when in a controlled environment like a studio, but this is almost pointless when all you need to do is swap memory cards and you're ready to go rather than wait for the transfer to complete.
Then there's the never-ending battle with the interface cable that always seems to be in the way.
The cable loosens mainly because it's only a USB connection that barely snugs into it's port. Making this more secure would be a major improvement. I would even be willing to put up with the slow speed if this were a bluetooth link to the camera. (*hint* *hint* *hint*)
As was pointed out in one of the other reviews, the manual is all but useless, therefore, your best option would be to go on line and search for how to program this unit for use. (The manual is obviously a poorly translated version of the Japanese one.)
If this were married to a 4G network and made less of a beast when it comes to power (yes, one battery will last about 1 hour with light to moderate use,) And this could easily be a world beater, but alas, it's not much more than an expensive toy.
It's handy, but not even close to an improvement for your productivity. If Eye-Fi ever releases an Ad-Hoc mode for it's Wireless card, the WT-4 will go the way of the woolly mammoth.
TFC