the cx550 xperts on here suggested these cards in either transcend or sandisk for the camera. i see the cards say either class and sdhc on them. which of these should i go with, i take it that class 10 are better?

Class 10 is faster. Should you get it? Well, in order to reliably record AVCHD video, the card must comfortably support the camcorder's maximum bitrate, which is 24Mbps for AVCHD. Class 6 supports 6MBps, which is 48Mbps (notice the difference between 'B' and 'b' in Mbps -- it is Bytes vs. bits). Class 10 is 10MBps (80Mbps). So, either will work for AVCHD (as a matter of fact, even class 4 should, as its speed is 32Mbps). So, the only difference between these cards may show when you copy the files onto your computer; class 10 will copy files master than class 6 (or class 4).

You should decide based on price vs. your need for fast copying of files.