[wallcraft]

1. No firmware for MOBI DRM on any 5" device (Opus has promised it).
2. DRM-free MOBI available on Mini and 360, not on PRS-300 and Opus.

For the BeBook Mini (EZ Reader Pocket Pro):
3. MOBI is ok. There have been some reports of hangups when reading MOBI, but you can recover without rebooting the device.
4. ePub is better than MOBI.
5. MOBI: Three font sizes, can add your own fonts. ePub: Five (soon 8) sizes, can add own fonts only by modifying each ePub (but you are creating your own, so this is easy to do).
6. N/A
7. Landscape available for ePub and most formats, but not for MOBI.
8. No difference between internal memory and SDHC card.

EDIT: I buy a lot of MOBI ebooks and I now routinely convert them to ePub using Calibre. I customize the look and feel using extra-css.