I cannot say this was my favorite or best one, BUT it certainly was an upgrade on the W123 and I really liked doing it --

Removal of the entire PS system and installing the mechanical (manual) steering box.
Although the very generous person who provided the same warned me that I would not like it, nothing could be truer.

From a total standstill, yes it is more difficult.

1-20 miles per hour there is a gradual improvement as you go faster where I really cannot comment on the difference between the two

20-40 really no difference

40 and over -- I prefer the mechanical / manual box.

I get rid of a bunch of stuff under the hood and lose whatever parasitic drag created by a pump. I can say the mod did the following also:

1. It gave me about 5 more miles on the speedometer. I easily hit 85 vs. 80 and still had some throttle to go

2. It improved my MPG by 2 miles per gallon, give or take.

3. It simplified the car itself, which is my personal preference.