I wouldnt be that concerend about the acc repair, just remember there will be things that will go wrong in the future to do with the repair, ie water leaks wiring faults etc.
I had an cat d disco and it was a good car but the things that went wrong
some normal landrover stuff but a few of the probs were as a direct result of the acc repair, mainly water leaks that took forever to find.
Still was essentially a good car for the 2 years i owned it.
If your eyes are wide open it wont be a problem.
Thing that would put me off any s class the most would be the air susp.
Lynall