In the past, I usually buy the fastest card they sell. Usually this means the most expensive card, and the top-of-the-line model, so reliability is unquestioned. Since buying these, I've never had a card failure or performance issues *knock on wood*. My conclusion is: to make a fast card, they need excellent drive logic (controller, high quality memory chips, etc.) which makes for a more reliable memory card. I have had cheaper cards fail.
Now I'm looking for a bigger CF card to use, 64GB cards or maybe the 128GB card (does the D700 even support this?), but the speeds are going out there! (I see some going 150MB/s) I know my D700 doesn't write that fast and my card readers, even though UDMA capable aren't able to keep up.
If I want the best reliability, should I still be going for the best (and therefore fastest) cards on the market? Or are they just sort of leveling out in terms of reliability?
In case you're wondering about speed, I'm the spray and pray type