Just sharing my personal experience with two Mehrans I kept and their ACs. I had two Mehran(s) 2013 that came brand new, one was VX version which came on road in Feb 2013 and the other was VXR and was on road in May 2013.
The reason I purchased VX in place of VXR was the reciprocating compressor that came f/f in the car, and this was the only reason I switched from VXR to VX at the last moment while finalizing the deal.
I got the whole AC system installed brand new in the VX same as it came in the f/f version but used the rotary compressor that comes in JDM cars like terios etc. Costing around 25k in 2014 (Used around 75k when sold)
VXR was factory fitted (used around 15 k before I returned the car back to office)
The cooling of both the cars were nearly same - but the fuel average of the car with rotary compressor was better by 1 - 1.5 kmpl driven on the same route. Also the VXR was white in color and had fabric seats in light color, while the VX was Smoke Green (darker) and the seat covers were black with artificial leather seats underneath so in my opinion the performance of the rotary compressor was a bit better too.
