My wife has had an MG3 for 20 months and has done about 10K. She is very pleased with it and no problems whatsoever so far.
Build quality looks good with no rattles or squeeks, and very spacious and comfortable.
I drive it whenever I'm allowed as it uses considerably less petrol than the 260
and really enjoy it. (The computer is showing an average of 44mpg at the moment). Great handling and very nippy if you are prepared to work the gears.
Jane bought it from Cambridge MG who we would highly recommend. Great trade in deal and they seemed very enthusiastic about the MG marque. Used them for first service with no issues, even offered to collect and deliver the car if required.
Overall excellent value for money given all the "goodies" that come as standard.