this is i guess highly opinion based.. but mildly breathed on cooper or clubman 1275gt can keep up with a pretty well sorted cento. Infact down a twisty i would say a modded cento stands no chance against a modded mini, would struggle to keep up with a stock mini on a twisty road. When i had the turbo seicento it would obliterate my mates 1275 on a-roads with sweeping bends and straights, but couldn't get away from it on a country lane at all.
But thing is the cento is mini-esque - small and fun and practical, just a mini is smaller and for just a drive on a sunny day i would say more fun. As something to drive everyday a cinq is so much nicer, easier to drive, comfier, sits more people easier, can carry more weight and is so much more practical - so horses for courses. For me one thing the cento has got is no-one expects a cento it be fun or even quick incase of modded ones - but everyone knows a sorted mini can be quick so you don't get all the bemused surprised faces in a mini you get when you roar past someone in a cinq.
Not gonna say a cento is better, nor will i say a mini is better - they are different things really even if they are both little cars.