It's such a special aeroplane - do a search on PPrune for any Chipmunk-related thread and you'll struggle to find a negative comment. Responses from the great and good as well as the newbies.
And it's an appeal that endures across the generations. At my club at the weekend I watched 3 youngsters being briefed for a variety of exercises on our Chipmunk, from effects of controls (a 15 year old ab initio student) through to a couple of guys in their very early 20's doing initial tailwheel conversion (from PA28) and initial aeros (an already Chipmunk-experienced bloke, despite his youth!)
Our Chipmunk has done 20 hours in 3 weeks - says something about its appeal