I had many people tell me that my Sansa Express would not work with a 4GB micro SDHC. Luckily I didn’t believe them and tried it myself. Works great, now my original 1GB Sansa Express has 5GB total capacity, somewhere upwards of 700 songs or so. I am going to see if it works with 8GB micro SDHC, I’ll get back to you.
As far as I can tell this is the best audio mp3 player that has ever been made (if it truely has infinitely expandable memory using micro SDHC.) This mp3 player does have some quirks, I am getting to be a bit of an expert user.