I've had the pleasure of driving one, Quite impressed really but I'm just not interested until there's a more sporty one (Lower setup, more aggressive styling, bigger NASP petrol engine).
The 1.8 turbo is fine, does the job. Just doesn't "Fizz" if you follow? Not at all interested about a diesel MG.
I know the mass market doesn't want a gas guzzling rocket, bot for me MGs are special and should always sit on the drive next to a sensible car to make up for the bonkers approach to motoring.
The looks of the 6 are definitely growing on me, and from my short experience you'll be really happy, cracking value for money - especially a second hand buy! As I said, bigger engine, more aggressive styling and I'm won over.
Best of luck with her!