Review...after AirCon pipe insulated...Good or Bad ?

In my previous car, I can easily tell if I'm using outside or recirculating air....

When the fan knob is turn to high at the 3rd out of 4th speed, it will be noisier in recirulating mode as the fan are sucking air from inside the car....but if will be quieter if using outside air.

And of course, recirulating air get cool down faster. Unless I'm wrong here...

Yes of course recirculating air gets cooled faster. Unless of course you are maybe like in Genting where the outside air might be cooler than the inside of your car. :-)