Anyway, while driving back I thought that since the roads were rather quiet I'd give Dynamic mode a try (the MiTo has a switch with Normal, All-weather and Dynamic options - the latter being Alfa-speak for "sport mode"). The first thing I noticed is it makes the steering feel heavier - no, it hasn't switched off the power steering (I know what that feels like from experience), but there's definitely more effort required.
The second change I found is it swaps in a very aggressive accelerator map. I did know that Dynamic mode would change the throttle map, but I didn't expect quite this much of a change and consequently fluffed a lot of my gear changes on the way back (through having more power than I expected when feeding the clutch in). Interestingly though it did make my 1st-2nd changes better.
Finally, it actually made the car feel more stable through the southern exit from the Station Roundabout. Normally it has a tendency to understeer and drift out of the left-hand lane as I accelerate round, but this time it hugged the corner better and didn't seem to need as much steering correction (it also felt like the amount of steering effort needed was more constant). Now, I know that the MiTo has an electronic Q2 differential that's only active in Dynamic mode, so I wonder if this is the effect it has?
I stuck it back in Normal mode for getting into the flat's car park, because a twitchy throttle did not seem like a good idea when trying to do slow-speed manoeuvring (and light steering is much nicer when parking - I have tried parking without power steering before, and it's no fun). But I can see Dynamic mode being worth another try. Perhaps next time I take the twisty turny road over Bury Hill?