If I remember it correctly we got the BoB FM in the 4.01 patch from mid 2005 so we already have it
From the 4.01 readme:
"4.01 introduces the next generation pre-Battle of Britain Flight Model (FM). In this add-on we are introducing a part of the FM from our next simulation."
Seriously - IL2 is good enough so any improvement is just a bonus. Sure the turbulence handling could need some tweaking and the ground handling feels a bit "scripted"... And maybe some multi engine prop/torque stuff... And...
