I have worked for them a couple of times over the years (80's-90's) and thought that they were OK.
One of the best things was that they didn't hold a 'grudge' if you left, and were therefore happy for you to rejoin the company again later (which couldn't be said for all ATC providers at the time!).
As for the salary, they always seemed to pay the 'going rate'.
All-in-all, not a bad outfit.
Imperator1300