IL2 with Pacific maps and planes.
I personally love it, the RAAF New Guinea campaign is an absolute blast.
A lot of people complain about the lack of flyable torpedo bombers and there's plenty of the usual FM/DM pissing and moaning.
Carriers are great fun.
As a stand alone game, I wouldn't reccomend it, there just isnt enough game content to carry it, but if you allready have Il2 :FB/ AEP then it is deffinately a worthwhile expansion, in fact a 'must have' if you are into the Pac theatre air war.
Flight model/ damage model, it is pretty much the same as IL2, ditto for the view system.
Plenty of new maps, ranging from a million square kilometres of nothing but water, to Midway and Wake islands, which have buildings in their correct historic locations, paths in the right places etc.
The New Guinea map is cool, but not very realistic, the Owen Stanley Mountains, 11000 ft jungle covered monsters, is a small range of hills in PF

Graphics are excellant, AI is passable, online it is stable and fun with the right crowd.
If you haven't played since the IL2 demo, it's definately worth grabbing a gold pack with the whole series.....if you have Forgotten Battles and the Aces expansion pack, it's just more of the same, slightly tweaked, in the Pacific with CVs.