I worked for AR at STN in between flying jobs and found them to be more than reasonable, acting in a professional manner. The letter you got through a forward at work seems a very over the top reaction. Passenger Service and Ground Handling Agents at STN come and go and AR along with its clients operate a constant revolving door with employees. The interviews are casual by nature. I must point out that my parking was covered on all occasions but if it wasn't I wouldn't have reacted as strongly as your letter writer did. My reaction from an employers point of view would be..." probably not the type of person we are looking for anyway".
In answer to your original question... I found AR to be a good employer in that the type of servicethey offer suited my needs for a period of time untill it was time to move on.
GP