On the subject of useable performance , I like to have enough that I can overtake safely on A roads when caught behind a slower moving truck or suchlike , but otherwise am content to pootle around mostly within the speed limits ( might very occasionally have a bit of fun on a quiet , twisty road ) as I like keeping my clean licence .
For me at least , I feel that my 300SL-24 has 'enough' performance for my needs ( mostly cruising along , top down , on nice days ) and has the added benefit of returning close to 30mpg , which I wouldn't get with a 500SL , the extra performance of which I wouldn't use . Similarly , with my 190E , I'm putting in the 2.3 engine next week , which should see it go decently enough ( the present 1.8 engine is definitely underpowered to the extent that overtakes are often not 'on' ) but should not incur the heavier fuel consumption my 190E 2.6 ( lovely car that it was ) did ; nor do I need the extra performance or maintenance regime of the 16 valvers , so I think the 2.3 8v will be the 'sweet spot' for me .
While I'm not always obsessed by spec , I do like some toys : hence I will get round to sorting the non working a/c on the SL , not bothered that the 190 doesn't have it as that will primarily be my winter car , and will be retrofitting cruise control to both cars when I get the required parts ; beyond that I can live with the cars as they are but not averse to retrofitting any other genuine options I might come across .