Well next time there is a discussion on which is best then I will allways say cf, My second 4gb microdrive failed after 6 months the other day on a shoot and I had to go tethered to my laptop which was very restricting. Before anyone says I've had one for 2 years and no problems then you were lucky. they were never dropped or anything, they were kept with kit cloves knowing how fragile they are.
I will never use a Microdrive again, I got a 4gb Sandisk Ultra II in the post this morning and all I can say is WOW it is fast in camera (1ds MKII) and uploading on the pc. rant over so if anyone is thinking of getting a microdrive think again you may be lucky but with the CF you get what you pay for.
I just tried to order another 2 cards and there out of stock.