I purchased my 99 E300 new and now have 53K miles on it. The car has been very reliable with only minor problems covered under warranty. The engine has been totally trouble free and runs like the day I picked up the car. The only problem that I didn't expect was to have to replace the rear window regulator so soon. I have since learned this is a common problem in the W210.
I have taken the car to several different MB dealerships for service and they often comment that the E300 is "bullet proof." I assume they mean they see very few problems with it.
This is a great Florida car but I'm not sure I'd own one if I lived in a colder climate. I owned one in Colorado and it didn't like cold weather at all.
Quiet, fast, spacious and very fuel efficient. It's hard to find another car that can fill that bill. Give one a drive and I think you'll be pleased.

__________________
99 E300 133K
98 ML320 99K
87 Saab 900 Turbo Conv 123K