It all depends on "how fast you want to go?" as someone else in the forum just said in another response. I have three Mercedes that all run pretty well within their limitations, but I have a Corvette that will do 160+, if only I had a place to do that ?! My 89 420SEL is similar to your S model and it is not a record breaker off the line, but will perform well in the 70 to 100 range of cruising on the Interstates ..... These V8's are not meant to be true speed demons, but they do have many other good attributes as you mentioned.

Get an SL to go with your S and you will be in good shape!

__________________
Ben Harrison Carter
1999 Mercedes ML320 87K
1992 Mercedes 300CE 89K
1995 Corvette 29K -- Sold Dec 09
1989 Mercedes 420SEL 99K -- (Sold 4/08)
1968 Mercedes 230S (106K) (Sold 9/06))
1976 Mercedes 450SEL 130K (Just sold - 06)
1961 Mercedes 220Sb (sold years ago)