My 300SD seems to have more power than I will ever use. I'm rather impressed with its hill climbing ability, too. Not slow by any means! When the light turns green I'm way ahead of traffic in a matter of moments.
And actually, my 1968 200D with 55 horsepower that used to be my daily driver was more than adequate for freeway driving. I found that most of the time I was tailgating cars in front of me while merging into traffic and most of the time I was cruising at 70-80 MPH in the fast lane. Even this car was faster than several cars I have driven. It felt like having a small V8 under the hood! It was peppy and the only times it ever seemed slow was when I had to climb a steep grade starting at low speed. After driving a 200D as a daily driver for over a year I will never call one slow again!