I believe in having a car's alignment spot on, but from experience I am very hesitant these days to simply let even a well recommended place fiddle with my car's alignment unless I am really sure that it needs to be done! Especially when fitting new tyres if the car "felt" fine when running on the old tyres on. Rather have the new tyres fitted and see how the car feels bearing in mind that the new tyres have to wear in. If the car feels off or you suspect/notice uneven tyre wear then obviously have the alignment checked and adjusted correctly.
I've experienced the blunders of alignment wrecking a car's character even when the complete opposite should be the case: Car goes in with standard rubbish steel wheels (all badly made or all running slightly untrue) and cheap nasty budget tyres that are worn and have some flat spots. Fit new alloy wheels and performance tyres and foolishly allow them to check and adjust the alignment. The outcome (before and after) - where the car wasn't the most pleasant to drive on the open road it still felt stable and you felt confident. It also seemed to cope with road camber and if anything would pull slightly to the left - off the road rather than into on-coming traffic. So with the new wheels/tyres fitted and the alignment done the car felt twitchy and unstable, was very sensitive to road camber and crosswinds, and worst of all it seemed to "favour" going to the right - made the car very nerve racking to drive at times. Had the alignment adjusted a few times trying to correct this and eventually just got use to it.