I have Servo-tronic, personally I think its a waste. I had to get it because all the cars at the dealership had already as an option. I think the steering is much more vague with Servo-tronic, not nearly as precise. The big advantage of Servo-tronic is for low speed maneuvering for parallel parking etc. it requires less effort to turn the wheel (big deal).
In the end boils down to preference, if your prefer sharper handling - forget servotronic, if you prefer easier maneuvering at low speeds get servotronic.
I suggest you test drive cars both with and without and decide.