one of the great things about flash has always been the latency issues, if you hammer the card with IO then it will performe much faster than a hard drik, same for bandwidth provided that the flash chips have been wired correcttly (funnilf enough it is posible to make a flash drive that does the 3gbps of sata 2 with current technolagy, just put those flash chips in parrellel)
microdrives have a maximum power consumption on spin up, so if you keep parking the heads then truning it back on you drain the battries quick (note to zsh users it keeps flusing to disk every 5 secs so avoid it if you prak the drive heads or use laptop mode to save power)
i would say trisoft has had a bad experince, others have done it with great sucsess and if you know a bit about partioning and the cp -a command then you really should not have a problem
trisoft: did you have a swap file on the card, i have heard of some flash cards dying like that but sandisk has a good rep. also i have heard of really good fakes on ebay that are hard to tell apart
os to sum it all up, there is a slight power saving with cf, a tiny spped upgrade and a huge IO per second upgrade, if we used initng we would see an increse but for anything else perhaps not
if you listen to mp3s it might be a good option depending on your choice of media player and how aggresive the buffering is as well as how "hardcore" you have been with the power managment (ie did you do kernel parmater tweaking, hdparm stuff and enabled laptop mode)
i would say go for it but then again you probbely didnt need my advice