I have performed some measurements last season using a bmp085 sensor running at roughly 40Hz (I recall, no oversampling anyway).
In my Pilatus B4 I had it mounted behind my head, between the wings.

I could see an effect when I was rolling over the ground during winch launching, where pressure increased slightly.
I could also see perfectly when I opened my airbrakes, which made a very sharp drop of roughly 20 meters. When I closed them the value restored to the old
value again.

I have not yet tried a wide variety of speed ranges, nor have I been able to compare the reported altitude with a GPS receiver. That is planned for next
season.