I had a w126 that wasn't in terribly good shape when I got it and I didn't mind fixing most of it, I just felt like getting the A/C and heater working was beyond my skill and I didn't really know where to start so I never tried.

Other than that it was much easier to maintain, for example the shocks took me about 45 minutes to swap all 4, and on the w210 I bought a set of shocks thinking it would be easy, and after hours of fighting with it to even try to get one changed I gave up and put it back together with the old parts. I also hate the ABS on the w210, although other than just driving it is fine. I am going to put a little more effort into getting it working again, but I would not be comfortable taking it to a shop with how fast the bill would climb with no idea if it could be fixed for less than just buying a new one.

I know no old cars are perfect, i mainly posted this because I was wondering if buying a w123 or w126 with the plan of repairing the A/C later was reasonable, or if its just not a car you buy if you care about that stuff working.