I've changed summer tyres to Conti Sport Contact 3 (245/40 18), the difference they've made is indescribable. They actually ride better than my winter setup of 17s and non-rfts. The car is what it always should have been. As to the qualities of the Conti rubber itself I will have to do a lot more miles to be able to comment with confidence, initial impressions are great though. My car has done almost 2 years now and I've never gone for wheel alignment. Tyre wear has been even, steering does not pull. Should I bother or should I follow the if-it-ain't-broke-don't-try-to-fix-it logic?

p.s. performance wise (apart from the ride and noise aspects) the Potenza RE050A RFT has been the best tyre I've ever owned. It grips and grips and also wears very well.

 

I've just put on new 172M's and after 2.5 years will be going in for a wheel alignment, I have no noticeable problems - but there's nothing wrong with a checkup !
My tire fitter also uses balast on the driver side to simulate real life weight distribution with me in the car.

 

If the wear was perfectly even across the old tyres, I wouldn't bother. There is no better measure of the wheel alignment than tyre wear over 20,000 miles.