The AC system in the 1996- model year MB's is the newer variable pressure compressor system, and it seems to work very well. Even in 100F temps, it seems (in most models) to get to a 50F temp drop, which is serious cooling.
We found the AC in our 1998 E300 very capable and never wanting, even in 100F temps. I imagine the W211 system is probably VERY capable, and as good as any to be found. MB systems were thought of to be quite weak, and the complaints piled up, so I would think later is better for AC power.
I rode in an older high mileage LS400 one very hot day, and it cooled very well.
1998 C230 "Black Betty"