Looking at both 2003 models but I am not sure how the CL handles high speed mountain driving. I had an SL and have no complants. These would be used for touring the western states. The SL I had did not have the power that I wish. Is it worth another 10K to 15K to go up to the 55 motors in either model. I do not have a need for the rear seats on the CL but they are less money. How does the CL handle compared to the SL. I spend most of my time in states that allow me to drive a little higher speed than normal. The SL55 is very nice but is at the high end of comfort for me.
Kevin

 

The SL will out handle the CL. What year and model SL did you own? If it was a 500, power would be about the same but the handling should be much improved. How fast do you want to drive and how fast do you want to get up to speed? Our 500 has plenty of power and cruises just fine. We don't push it too often but it's plenty fast for usand the handling is also outstanding. If you want a barn burner, go with a 55 but you have to weigh the cost/benefit and see ifit's worth it to you. Top end on the 500 and 55 are governened at about 150. The difference is the 55 will get there quicker. Also, you are comparing a roadster with a hardtop to a coupe. Two different cars with different purposes. Can't go wrong with either choice!

 

The handling of a SL compared to a CL is two different worlds. Power in engines is the same, but the SL is more made as a sportscar. Personally I would go for a CL, but only because I need the extra seats...
Anyway, both are fantastic cars and you'll love them both, regardless which engine you choose. 500 versus 55 has some clear differences that you would like to test out, but the top speed is anyway the same unless you get a new software flashed where the top speed is cut away.