I have a 5dIII. And had a lot of sd (big, small, fast, slow) cards that I used in my older camera.
For the 5dIII, I bought a big - slow - compact flash, and, in addition to my standard sd cards, I bought a very fast SD card.
fast SD cards are a lot cheaper than fast compact flash..
I also gave a try to a very fast and expensive compact flash that my wife have for her 7d.
To transfer to computer, I notice no differences. I have an integrated card-reader in the computer, and, of course, fast compact flash goes fast, fast sd goes fast, slow sd goes slow, and slow compactflash goes slow...
I also didn't notice any difference when shooting, with the 5d3. fast sd goes fast, fast compactflash goes fast...that's all. So I try to have always 2 cards in it, one primary, fast, and the other as a "second" when the first is full.
So finally, for me, this debate is a debate about the cost of the cards..