I know in my stocking is a 720 and I have been reading on getting at least a 2GB SD card. So on Friday I picked up at Best Buy a SanDisk Ultra II 2 GB for $26. Now in today's paper they have a 4GB SanDisk 4GB for $35. Was wondering if I should stick with the 2GB Ultra or trade in for the entry level 4GB for another $10? First inclination is 'Bigger is Better' but not sure if the plus of an Ultra II is not better for the 720.