Thanks for the detailed answer.
No major work done. Last year AC pressure valve plug leaked. It was replaced with a kabuli. gas was refilled.
I am thinking to go at universal car AC in G8. I have heard good reputation about Abu Bakar on pakwheels thread. I don't have measuring equipment myself and Ustads usually don't listen to what customer is saying. They just check using their own terminology and give a quote.
My car is regularly serviced at Techno Wash station near DHA2 islamabad. I will ask them to pressure wash the condensers. As far as i can tell, they are usually clean. I am a layman in terms of cars and engines.