I've got the 17" MB Pro with the 256gb SSD and the wintec 48gb card. First performance is just awesome and very appreciated. I mainly shoot tethered to the MBP and then use the wintec espresscard as a shuttle to move files from the laptop to the desktop as its super easy. Note that I don't store the tethered files directly to the wintec but rather make a temporary copy or backup to the wintec then move so I have a working backup in all steps. After using the SSD and expresscard, I'm thinking hard drives are on their way out except for mass storage. I did read digilloyd's article on the SSD's and figured I'd do the formatting he recommends at some periodic interval but haven't seen any slowdowns on either card so far in 6 months or so.
btw - My experience with O W C has been mixed though - seems like the last two ram orders I purchased from them had EEC errors and had to be replaced. Also before that both mercury elite hard drives failed. They did replace but what a hassle and bunch of wasted time. "The bitterness of poor quality remains long after the sweetness of a low price is forgotten"
