Class 2 is fine for 720P recording. The choppy playback that some people have is 100% software related. Would putting a higher class solve it, sure it would. But the fact of the matter is a class 2 is more than sufficient. Not sure how long some of you have had your Evo, but I've had it since June when it had 2.1. The choppy playback was NOT an issue with 2.1. It was when the Evo's got the 2.2 update that people started getting issues. Complaints came in almost immediately. As a matter of fact, complaints about the choppy playback after 2.2 was coming in even BEFORE the "official" 2.2 update. Not sure what exactly is causing it, but it's not the SD card, it's a software issue...