I have a i7 960 cpu, which is a quad core running overclocked at 3,6 GHz.
It runs with a NVidia GTX480.
So both my cpu and video card are quite old now.
The Stuka has a small impact on the FPS but it's not critical. In fact, the general FPS impact is much lower than their Baron B-55 for example, which is almost unflyable on my system (unless I set the FPS to unlimited, which I don't do anymore). In fact, I might compare the impact of the Stuka with their Sabre, perhaps just a bit more, but I haven't tested the Sabre since quite a while (I'm more into the slow planes currently).
The 3D model is really, REALLY cool, especially in the cockpit, which is simply magnificient.
The sounds are nice, but I'm not totally happy with them, I can't exactely explain why... it's just a feeling.
There is a siren, but its sound seems, on my system, to run a constant speed instead of varying with speed.
The flight model seems to be fairly realistic, but I'm no expert there. The behavior reminds me of the Stuka in the early IL-2 series, which is a good start I think.
There is a load manager which is quite well done, if I remember correctly.
EDIT: nope, I don't remember correctly
I just launched a flight to test, there is NO load manager, sorry :/
There is a special "auto-recovery" diving mode which is interesting, but the bomb you drop has quite a strange behavior in my opinion.... the impact location seems off.
Overall I have to say I'm quite happy with that plane.