I'm not a real P-47 buff, nor am I skilled enough to fly those planes regularly in combat, but with the recent FM updates the P-47s are lethal in FB as much as in AH - when used right.
The E retention seems pretty simular to AH, and the dive acceleration is good. The problem is, roll speed is still a bit off. The low speed roll is a little too high, and the high speed roll is a little slow.
Also, the vibration when all 8 guns are fired are a bit harsher than compared to AH, which scatters the rounds a lot more than in AH, but still it is lethal firepower.