A few years ago I had trouble with Hitachi CF 8GB cards losing or scrambling images in the Canon 30D, so am now leary of larger cards.
I found yesterday that I didn't have enough memory for the large sized files, so set the T1i for smaller images. I didn't like the results, and so want to resume with the larger. But I'm hesitant to purchase large capacity cards until I hear from some of you folks. If you're using large capacity SD cards, please let me know how they're doing for you.