I use mostly San Disk Extreme CF memory cards for sports and wildlife photography. I was in the US recently, pretty much in the middle of nowhere, and I ran out of capacity so had to buy some San Disk Ultra CF cards as these were the only ones available to me.
Now I know the read and write speeds to the cards is different but do people find it impinges on their photography using the ‘lesser’ ultras rather than the extremes or extreme pro;s?