Hi Tek
Would like to share my experience with my SGS II.
So there have been a lot of "rumors" and stuff about this phone and its firmware on the internet.
Since i got tired of all that, i installed Replicant OS found here: http://www.replicant.us/
And what i got was a fully functioning phone, (Except some few services, bluetooth etc.)
The interesting and frustrating part of the little story is that the firmware, (Modem in this case) kept trying to override settings in the phone, which caused some hickups.
Replicant OS seemed to do nicely, with isolating the modem. But it may turn off your phone entirely which has happened to me countless times
In the end i got: All that talk about not using phones, smacked unto face :D
Just wanted to share this