Its not always a simple case of Army QM's being not so good RAF being better. Quite a few RAF personnel based in London preferred to come to RAF Headley Court for their kitting than RAF Uxbridge as the civvy storemen at Uxbridge were legendary for their tightfistedness.
Some Army units also are not too bad, although I've never had to one for one exchange AA batteries at any RAF unit but I have on a few Army ones.
Report Line - I fully agree with you. Getting hold of kit you are entitled to shouldn't have to involve bartering to get it out of stores. I have always done my best to get hold of what personnel are entitled to and even if they aren't strictly entitled I'll see what I can do. Sometimes such things as a few extra pairs of socks can make all the difference when deployed.
Unfortunately many storemen/suppliers act as if they have to pay for the stock out of their own pocket which gives those of us who try to help our fellow service personnel just get on with life a bad name. Of course there should be some control on certain restricted kit to enable the small amount of stock to go to those who really require it but the system has plenty of flex in it if you know how to use it. Unfortunately my colleagues in Clothing Stores of a certain North Hampshire RAF camp seem to be firmly in the "you can't have it, someone else might want it" camp and even people who share the same trade struggle to get items they are entitled to out of them.