Mine came today!
I am using a TurboGrafx-16 with CD-ROM and YES System Card 1.0 will work on the Everdrive and run Altered Beast perfectly. The Games Express card boots up as well but I don't even know of any Games Express games to try, but I imagine it will work.
I have a Mac so there are a lot of garbage files that show up in the directory when browsing on my TG-16. Krikzz will eliminate these in an OS update I'm sure (I let him know about it). Not an issue if you mount the SD card to a Windows PC instead of a Mac.