I have had similer power loss with my galaxy 1.9tdi (130k) when going uphills.Changed the maf and power restored.If you take your old maf to gsf they will give you refund on old unit.Second time it has been replaced.
I have had problems with the a/c on my 2000 x reg 1.9tdi.It turned out to be an intermittant elecrical prob with wiring beneath the battery.I removed battery and checked wiring beneath,couldn't find anything obvious but a/c now works ok.