Let me clarify a few things. Unless I had a fair bit more money, I would never spend £12k on a car just for fun, and apart from the noise, the MY05 Impreza didn't seem raw enough to justify the other compromises.
Where as a classic is going to cost less than £5k, is going to be more focussed and would be used as a fun/weekend/occasional use car.
Fett's comment got me thinking how many times I've really had a chance to take a 4WD for a proper run, and that's limited to a few quick blasts spread over a Pulsar, a shoddy classic WRX and a MK4 R32. I have the opportunity here to give 4WD a chance, and to give me a chance to properly familiarise with 4WD and what it has to offer.
I don't really see what the issue is here?