MDD is very trustworthy and provides exemplary service. I've bought from them many times and always been well satisfied. More than once they've gone above and beyond the call for me. Highest recommendation.
I do shoot sports in RAW, and 8GB is an average soccer match for me. Clearing the buffer quickly can be critical to getting the next shot, and card performance really does matter.
I usually come home from a match with between 1000 and 1500 RAW frames. I can have them culled down to a hundred or so keepers, cropped, rotated, corrected and up on the web in about two hours. I'm really not sure how I could do it any faster shooting jpg's, and given that I'm very often pushing underexposed ISO 3200 images, the quality would suffer.