How about a slightly biased opinion... I do some illustration work for Classic, and have compared both systems side by side. There is a fit and finish difference between the two (classic is nicer, albeit most parts you don't see after installation), Classic's system has a greater cooling capacity (due to simple increases in capacity)... and... this is the big one, take a Vintage evap case apart and look the route the air has to take - strange engineering design, 40% of their airflow hits a wall and then has to mix back in at a 75% angle against the flow of the other air.