I do a hell of a lot of short journeys in mine, and after a while, even once it's properly warmed up, it can feel decidedly flat.
I recently did a 400 odd mile round trip, plenty of A roads, motorway, varied driving, and the car certainly felt much stronger after that. Now after more of the short commutes to and from work, I'm sure it's gone a bit flat again.
I used to think the old 'ECU learning' thing was a bit overstated, but with this car in particular there's something in the theory.
I think they call it the 'Italian Tune-up'!
Also, about a week after getting a new rev G dv, pcv and cam follower, the car seemed to get even stronger and smoother than the obvious improvement straight after the parts were fitted.
All that said.... I'd still get it down on the rollers at R-Tech. Just be sure of things.