newer microdrives are made better than the older ones, however they are still much more susceptible to damage than cf cards, microdrives are exactly what the name implies they are very tiny hard drives, thus they are more prone to damage if dropped, originally the only way to get a high gig card was with a microdrive, but now cf comes as high as 8 gig, so there is no advantage to a microdrive, the only reason I have my 4 gig is at the time I bought it, cf cards weren't available in anything beyond 512 mb,at least that was the highest I could find .... shooting at 8megapixel I wanted a larger card to avoid constant card swapping...I also didn't know about the fragile nature of microdrives until after I bought it, plus they are extremelyt slow, and generate more heat during extensive shooting, I learned this during an afternoon shoot in 90+ temperatures, was shooting away at my model and her horse, and my camera locked up, checked the microdrive and it was HOT...once I cooled it with my auto AC, I was good to go, 'till it heated up again, really killed the flow of the shoot....now the 4gig travels in my memory case, to be used only as emergency backup...
I would definitely look at getting a few 1 or 2 gig cards to replace the microdrive,
although Kelly has a good point for using smaller cards, my preference is 1 or 2 gig, to avoid constant swapping of cards which I've read increases the chance of corruption... there are valid points for both sides of the issue...