I have owned 8 New MINI's since they were launched in 2001 up until last month when I traded my F56 JCW for an Audi, due to the need to carry grandchildren and my daughters wheelchair.
As has been previously mentioned it is not a fair comparison between Classic and New MINI as other than initially sharing a similar shape (R53) and being front wheel drive, the New Mini is a modern car with all the luxuries and safety features we expect these days.
I took my 231 BHP JCW on the Top Gear track last year and was following a Classic Mini Sprint with a 1293 engine in it, there was very little difference in acceleration and cornering but the suspension and braking was the main difference with the JCW able to cope with the bumps better under braking and did not suffer from any brake fade.
I am a fan of both Mini and MINI but my option recently was either trade in the JCW or sell my GT, needless to say I still have my GT.