We have a Chipmunk on our approval (rtf that is ) thats still on a C of A. And surprise surprise it flies just as well in IMC as it does in VFR.
Although I do agree its not ideal for IMC training.
The Chippie is an excellent aircraft in which to learn instrument flying! That's how I was taught 40 years ago in the RAF and neither aircraft nor weather has changed since then.
There's too much emphasis on radio navigation and playing airliners in little aeroplanes by some folk - and not enough emphasis on good, solid IF skills.