Is Keyless Go worth buying?

Very, very convenient. No problems with it for one year (2004 E320). Definitely would buy it again. I recommend ordering it. You won't be disappointed.

JoeC

Works very well. The 2nd generation system, on the 211 body, should have been the way they went from the beginning..... instead of those STUPID flat keys. 2nd generation looks just like the non-keyless go keys.

Yes, having it built-in to the SmartKey is great. The sensors on the W211 door handles are better than some other models, too. There is actually a small mechanical switch on the inside of the handle that is activated by your grip. You walk up to the car, put your hand around the handle and pull. As you do so, your fingers activate the switch and the doors unlock. Unless you are really trying to "beat" the locks, you'll never notice any delay in opening the door. On other models, say the SL/R230, they sense your touch by static discharge to activate the switch and it does not respond as fast - sometimes you pull on the handle before the door is unlocked.

I really cannot see any major advantage to Keyless Go other than as a convenience. I'm not sure I'd get it in an E350, but I would not hesitate to spend the extra $1K in an SL or E500, or S-Class.