A little update to this. I spent Tuesday at Sandown with a few of these MPS3s (plus a few other Mazdas).
I can say that the 3MPS is a mighty quick car at the track. Stock standard, road rubber, 4 up and aircon on and we still saw just on 200km/h on the back straight. I did take a new MX5 out at some point, and as a guide saw just under 170km/h with just me in the car.
The MPS handled everything thrown at it. "My" car actually ran all day with the aircon on, about 20 different drivers and was the first one to run out of fuel. So, imagine your road car doing a day at the track being driven by anyone and everyone, getting through a whole tank of fuel, half worn tyres and just happy to keep backing up for more!
To sum it up, a very worthy contender in the hot hatch range, and it would be my pick. Diff works well to put power down, power delivery is strong with a huge midrange, steering had very good feel, handling was good and more adjustable than the older car and the cabin was a very comfortable place to be. Car felt safe and secure enough for me to be sitting in the passenger seat, being driven by some who had never been at 180km/h and so were more intent on looking at the speedo than the corners just past the blind crest on the back straight. On that, why is it that a lot of people are happy to mash the accelerator pedal, but then at the end of the straight simply touch the brake pedal like they are trying to stop from 20km/h in 20m? While the look on their face when they work out they aren't going to slow down in time is priceless, it got a bit tiresome when it happened lap after lap!