Microdrives are not worth the heartache when they go bad before you've downloaded the pics on them. I have two 1 G micros, and a 340. One of the 1G and the 340 died in-camera with photos still on them. The 1 G drive lived long enough to barely download the pics, but the 340 was doa. My remaining 1G sits collecting dust in a drawer somewhere.
Just my experience, maybe I'm just unlucky.