My own feeling is that auto and sports cars just dont go together, i've got a manual Roadster, its got the usual problem of being a bit tight into second when cold but other than that its great, I waft along in a big diesel Merc all week and the auto box is ideal, it suits the car perfectly and I wouldnt want a manual, but at weekends on a nice twisty road I want a gear stick and clutch.

I once had a tiptronic Mitsubishi FTO and it drove me nuts, its the shortest ownership of a vehicle i've had, I bought it on a whim and then found all the problems that you are describing when I tried to drive it like a sports car, I got rid of it again within weeks.

My opinion is go for a manual.