Ok, here's my unbiased opinion.
The Merc is staid and would make you look like you're trying too hard in a mid-life crisis kind of way (which is bad).
It is not a German car made in Germany is it is crud. I've fixed US built Mercs too often, and unless it is an S Class, that statement is true.
The Merc will hold it's value better, especially if you get it in imaginative silver.
The Merc is RWD
Not that you'd notice as the chassis is so so and the VDU kills any fun
The Alfa is an old design.
But is still looks cool
Dynamically, the Merc beats the Alfa
But it is as much fun as Herpes
You think the Merc is stylish.
The GT is stylish.
The Merc makes you look like you're dressed in a million dollars.
Remember the Emperor's New Clothes
Did you really think you would get unbiased opinion on this forum?
Oh yes, buy the Merc.
Methinks the Alfa has it licked in every important department, and the first and most self defeating one for Merc drivers whose image is all important to them is how others see them- end of