Speed perception is a difficult thing to debate accurately, it's something that varies greatly from one simulation to another and since i don't have any real-life experience of flying fast aircraft in close proximity to the ground or other aircraft, i can't make any educated guesses.
That being said, the aircraft we currently have are somewhat slower and turn better than the late war hot-rods we were used to in IL2:1946 and the gunners are not as dangerous, so people tend to chop their throttles more often if that lets them get off a couple more seconds of fire on the target. In other words, we generally fly a bit slower for a variety of reasons.
Finally, the new flight model has more pronounced inertia effects and in combination with the slower speeds used, sometimes it all tends to give off the impression that things are happening on a slower pace.
I don't know how accurate it is, especially since it varies so much from one sim to the other, but it's easy to get used to it.
Welcome aboard and enjoy your stay
