I am so very glad that I left NATS when I did ! (before station grading). I was at EGPD, & as far as I am concerned , it was amongst the most demanding stations they had. Likewise at Jersey. When I arrived there, it still had some traffic, & was the 3 rd. busiest Unit in the country ( in the summer). So, money well earned !
However, I do not subscribe to station banding ( or whatever it is called). How do you grade a station ? Yes, EGLL & TT are far bigger & busier than PD & JJ. But they split the traffic between many more sectors & controllers. Everything comes at them from the same direction & at the same speed. They have more airspace to play with & more procedures to deal with it. In my experience the chaos that ATC has to deal with at a place like EGBE is far more demanding of the top rate for the job.
The union sold the rest of the units down the river when it agreed to Station Grading !