Contractorisation has been around for donkey's years and, in my experience, has been a disaster. HQSTC was the worst. Good food but the staff were all students with a less than acceptable grip on the Queens English. I remember a receptionist, who spoke no English, trying to call a Practice Fire Evacuation on the Mess tannoy once, very amusing but a little worrying if she had to do it for real. That was in the late 90's so things may be better now.
Interestingly, they always brought in RAF Stewards when the wheels were Dining In.
No experience of PAYD but it seems very popular amongst the younger elements. Must admit, the many years I spent as a Liver In I would have jumped at the chance top opt out as Mess food has never that exciting. Also, some of the bloody stupid rules sometimes in force. In the early 80's we had a PMC at Buchan who insisted that all Officers wore jacket and tie for breakfast and beans were banned from the menu as they were not considered an Officers vegetable.
Sadly, I think the days of individual Messes with their traditions and 'extras' are numbered. What makes the pill an even more bitter one to swallow is the fact that we just know the alternative will be cheap, nasty and poorly thought out, with you and me figuring at the bottom of the list of priorities.
I've said it before and I will say it again. We are heading for the UK Defence Force which will eventually be swallowed up by a bigger, even less efficient, EU Defence Force. Ear Rings and pony tails will be the norm with uniform only being worn at your place of work.