In its heyday (a bit before my time) I seem to recall reading that in terms of movements it was 3rd busiest airfield in the UK, after LHR & (I think) MAN.
When I was there the AST fleet was 15 C150s, 14 PA28s & 8 C310s. There was also the Scottish Aero Club & quite a few privately-owned a/c. Tayside & Edinburgh Air Centre also came for training & exams. I remember having a good half-dozen in the circuit and a similar number arriving/departing, as well as the hold full up. Movement numbers must have been well into the hundreds/day at times.