As far as SDHC SanDisk cards there is a base? model I don't use or know then
The SanDisk Ultra II card is a 100x speed equals 15mb/sec.
The SanDisk Extreme III card is a 133x speed equals 20mb/sec
The extreme card seems to process a pict about twice as fast as the Ultra II, press mark, count one, two, then pict is done, before U can usually say three.
I don't use any other brand of card then SanDisk because in early spring of 07 some folks reported problems with offname type cards, seems as tho the cards would work maybe once then not work a second time, sometimes reformating helped other times no help, but SanDisk cards always worked so being lazy I took/take the easy way & use SanDisk, over two seasons of pict taking & never a card problem except time I forgot the card>>>>>>>>>