Have a 2010 E350 and it's a very nice car. MB's are pricey, as are BMW's, Audis and anything made in Europe. Main reason is the options that have to be added to get to the same level as Asians include.
The MB E is not going to ride as well as a Genesis, even if you get the Luxury version, which I did. German cars ride stiffer and are designed for that purpose.
I've considered the 2017 E, but the front end is not attractive at all. MB and most German cars have often confusing navigation, audio, phone, etc. electronics.
Oh, and I prefer it, but the gear shift on E is on the column.
Rule of thumb for German engineers is: If it can be done in 3 steps, lets make it 5 or 6.
As for reliability, the E is the most reliable MB, but that ain't saying much.
If seriously comparing, you need to get a complete list of all the features and options. Those are often only found in printed brochures for some reason. The one for the Genesis G80 is excellent in this regard.
Then compare what comes standard on each and what options you want and how much they will cost. MB, BMW, etc. will add huge costs just to get the standard safety features on the G80.
Of course, maintenance is another cost. Some manufacturers include it in intial price or lease, but YOU are paying for it one way or another.
Maint. on my MB runs $400 every other year and $1,000 the other years. You can do some yourself or get an indy. But here again, they are very complicated and much more difficult than Asian cars. This leads to higher prices.
When you narrow it down, take candidates for a long test drive with lots of varying conditions. And tell the sales person to shut up while you are driving.
One thing I do when getting a new car is to get a printed brochure for each, then when narrowed down to final 2, 3 or 4 I lay the brochures on a counter or bed and compare pictures. The most important picture is the dashboard because that is what I will be looking at almost all the time.
Good luck on your hunt and let us know what you pick. It ain't gonna be easy.