I'm looking to buy the canon 7d when it comes out which uses CF. These new memory cards just released by SanDisk can transfer up to 90MB/sec. That's great and all, but they cost hundreds for even the small capacity ones. So the question is: how much transfer rate in memory cards do I really need? I think the camera has its own buffer in which it stores continuous shot data while it transfers onto the card, so.. the faster the card the faster it gets cleared or is there a limitation in the camera itself? I'm looking to get the best performance that I can, even though I may not need it all the time.