About two months ago I did exactly what you're contemplating - handed back my 3.2 and took a 1750.
I miss the noise (a wee bit) and the 4wd (now and again), but overall loving the TBi (and the fuel economy!)
To be honest, cars of this complexity are quite an undertaking if not in warranty. I had a few problems with my 3.2 and wasn't happy to take it on as a "going concern". But who knows, maybe it will be flawless for the new owner...
The TBi feels nice and urgent when required, so no complaints on the rapidity. If it was a wee bit noisier I'd be more happy, but hey ho - I've got three years of fixed price motoring, and that's important to me.