I would like to point out couple annoying issues that still exist in lates firmware (A.10.60.03) for under win7 .
Why I need change to change S21 to B to do Power receiver calibration?
It is pretty annoying that you can not calibrate RX receive without switching the parameter to R, A,B,C or D receiver. You have separate menu for power leveling and calibration, so why not defined what source and receiver you like to use for calibration in there?
There more: If you perform source level with enable reference cal, and afterwards you perform S21 response or vector cal, it remove R1 receiver source calibration. If you perform first S21 response or vector cal and then Source level with reference enable, the R1 will be calibrated. There should not be dependency which of the calibration is first or second.
It will be good idea look in that and do some cleaning up some small annoying thing in FW.