Roger Calver ("Vestinious" firmware) and Lefeudedieu ("Relax" firmware) have got together and - with Mp4doggie's blessing as boss of Slatedroid - released a beta for "Slatedroid Mercury" intended to combine the best aspects of both Vestinious and Relax as well as reviving the "Slatedroid" line of firmware.

I've installed it on one my M001 devices. The first boot takes between 10 and 15 minutes, but after that it's all normal and the firmware does what it sets out to do:

1. Android Market works out of the box.
2. Can get root access easily
3. swap partition used automatically if it is /dev/block/mmcblk0p2 (2nd partition on the sdcard)
4. Looks good. As fast and responsive as any of the best firmware released to date.

You can get it here.  

This firmware also works on the M002 tablets as far as I can tell.