I am loving this 01 E55. It has room for the family, a nice size trunk, I am averaging 23.3 mpg going back and forth to work, it has a nice firm ride but still soaks up the big bumps, and it's always willing to make quick work of passing the slow folks.
My fiance' even likes it, and we usually clash when it comes to taste in cars...
She likes huge lumbering luxury barges, and I like anything that will get me in trouble lol.
The only downside to it is the odd attention it has gathered at work.. I keep getting called "high roller" "big boss man" etc Then they remark at how expensive it will be to keep on the road.. I laugh it off, knowing they paid much more for a much more boring car than I did, and that they really are not THAT BAD to keep on the road.. I do all my own work.

 

Congrats mate! Hope you have long miles of comfort, safety and FUN.
As long as you do your own work you're in the safe, because labor is expensive (at least in the North).
Parts are very cheap compared to newer Mercedes\AMGs.
So no worries!

 

The W210 is very solid car. Very comfortable and reliable. Plus, the MPG is really good for a big V8. I once drove 430 miles in 1 tank of gas from Los Angeles to San Francisco and still have some left in the tank.