Ok, so I jumped on that $20 deal the other week for the Sandisk 16gb Class 2 card. There were a lot of people brushing it off since it was only a class two card. I bought it for the space to $ ratio being so great, figuring it'd at least be as good as the stock card.
All in all I'm very glad I bought the card, the initial results seem very good. It seems to have both higher sequential and quicker random access times.
I used HD Tune, if you'd like additional runs put on both cards I'd be happy to do so for a limited time.
32k run:
8gb card
16gb card
64k run:
8gb card
16gb card
128k run:
8gb card
16gb card
256k run:
8gb run
16gb run