Android 2.2 (FroYo) firmware[]
Die Firmware Firmware v1.0.0.932 Revision 1.0 - European Edition lässt sich problemlos auf dem meteorit MMB422 installieren.
Android 4.0.3 (ICS) firmware[]
Some users tried the Atlas 4.0.3 ICS firmware with succes. See [1] It's practically the same fw as the Pearl firmware, no usefull add-ons
Another user tried Himedia Q5 firmware on his Veolo without any succes. [2] That's due of the very different hardware of the Q5 and also a difference in NAND chunk and page sizes.
At this moment the Pearl FW seems the best choice for your MMB-422. A big disadvantage is the size of the data partition, it's not big enough to install e.g. XBMC or Chrome for Android.