I could really use WIFI with my 5D mk III for several reasons- * Product Photography for my wife's Ebay - the "studio" is on another floor, and to have the photos uploaded automatically would be very helpful
* Remote control / IPAD -
Given that it may not fit in the body or drain power too much, I would suggest a Mega "Grip" with: >Extra Batteries >WIFI > GPS > ST-R3 remote flash controller
I just returned my Samsung SSD. I built up a system with that as my system drive and a pair of 2 terabyte drives RAID'd for data. After the 2nd time the drive deformatted itself spontaneously, I lost faith. But it was fast when I had it.
My son got the best deal- he was working at a rummage sale, and there were a bunch of old style TV's (not LCD) along with some old camera equipment. There was a Pentax ~50mm 1.8 lens, that went unsold, so they gave it to him. Since it wouldn't fit our Canons, it went on EBAY and sold for $140...