Brize was the same 5 years ago and it and Lossie I have heard the most bitching about by service pilots.
If you do complain.
1. As quickly as posssible they will try and move to the phone so I presume there is no evidence.
2. You will then be invited to visit so they can show you how busy they are.
3. They will try and keep it in unit.
Only time anything gets done is if a SRG ATC type person gets wind of it and brings it up outside the Unit.
Bring it up on PPrune and publically broadcasting issues with a unit have been quite successful in the past though. I am really sure the SATCO of Linton is not happy at all that his bosses down in London can see his dirty washing being discussed.