In going form the summer tires to the best of hte all weather tires, what does one lose? Acceleration, handling, ride comfort, noise...?

Really depends on the tire but in general expect:

-slightly sloppier handling (softer sidewall)
-ride comfort should increase (typically softer compounds)
-noise could go either way really
-shouldn't really effect acceleration

What make/model all weathers are you going to? I could suggest Nokian NRW/WRs but only if snow was a significant concern as that is where these tires really shine. They are pricey but will last quite a while- I've got over 25k on mine with plenty of tread for all but serious snow conditions where they let me down a bit this winter (3rd winter what more can I ask for.) As much as these impressed me I think I'm going to give the new Conti Extreme Contacts a go as I've read nothing but positive things about them and I think they'll handle closer to that of my summers and save me a bundle in the process.

Thanks, Zimmer26. I do not have hte car yet! But I had been htinking of Conti Extreme contacts because of hte good reviews.

Since if I buy a Merc I would be getting the E 55, I did not want to lose acceleration since one pays a lot just for it. Handling is not quite as important since the E 55 does not handle that fantastically anyway.

I wonder how much the handling would improve [givne your statement about sidewalls] if one used narrow sidewalls [e.g., 265/35]

I would say on a tire that wide and with that short a sidewall, it shouldn't be a big factor. When you said "all-weather tire", it made me think you were getting Nokians as that is (appropriately) how they refer to their NRW and WR tires that are really snows that handle well enough and wear long enough to leave on all year. Looks like the Conti has more of a performance bias while boasting good snow capability and a much lower price that makes them an attractive option for me. Good luck with your new car- this is the new E55 you're talking about? Awesome car, and I can't imagine that it doesn't handle extremely well for a car of its braun. If you can afford an E55 than you can presumably you can afford the best all weather tire the Pilot A/S. That's what I'd get anyway. Actually I'd probably go Pole Position summer/Nokian WR winter mounted on separate wheels.

Thank you for the advice and your good wishes.

Getting a car and being able to afford it are not quite the same!!!

I hear ya dude. For a while there (and sometimes still) I think screw the (horribly overpriced) house I want an M5 dammit! MB should really start at least offering manuals in AMG cars. If that day ever comes, I'd definitely take the E55 over the M.

Buying a car is not rational!

In my case as long as I can make my payments... Once I was spending about 60 percent of my after tax income on my car. Somepeople like durgs. Some gambling....