I played for a couple of hours in the Rabaul game.
Impressions:
Graphics
Superb on the whole; a good balance between detail and runnability. The cockpit art is excellent - the instruments in particular are outstanding, not quite so clear zoomed out but crisp and sharp as you move in. Controls, such as throttle etc move as they are toggled.
The Beaufighter cockpit is a work of art.
I didn't like the heavy dots of distant aircraft - AH does this much better. Terrain is good, tracers are nice and cloud layers are well done.
Views are like AH which is great. Six view is partly restricted, but not to a ridiculous extent like in WW2OL, for instance
FM
Challenging compared to AH. Engine torque is heavy and trimming is manual. Without working rotary switches on my joystick it is a complete pain in the arse to trim the plane using the keyboard.
At low speed planes need to be handled with more care - take-offs can be tricky if you have a heavy hand. Soon adjusted to however.
Engine management is quite detailed - I liked it.
Planes seemed to sink into the ground when ditched. Possible bug?
Gunnery
Didn't seem that different from AH. The only time I managed to get a gun solution was against zeros in a P-40. I scored hits without any difficulty. Nice hit 'smoke' sprites.
Overall: excellent game and well worth checking out.