I totally forgot about that free case,.. in any event, I have a couple of those cloth pouches that came with the last two hi mini disc recorders I bought and I kinda like using that. I have a butt pack that I've used for years for carrying my stealth gear (and my flask!). I have a couple of strips of the hook side of velcro inside the main compartment and that cloth pouch attaches to the hook securely. With the opening of the cloth pouch right at the top and attached to front and back of the compartment I can slip the M10 in and out and it's always in an upright position (I also don't have to worry about it getting scratched by the zipper).
Regarding micro SDHC cards, I bought a couple of Class 4 "TopRam" 16G cards on Amazon for around $32 each. I've run them through their paces and they seem to work great. One came with a USB card reader and I can transfer the files to my Mac pretty fast (using the M10 is much slower). I imagine that the class 6 cards should be even faster but when I transfered 8G it only took under 5 minutes so that's fast enough for me.
BTW, the card reader is a super cheap one and it's a pain to get the cards out without a pair of tweezers. Any recommendations for a nice one?
http://www.amazon.com/gp/product/B003C2SQ9K/ref=oss_product