The 205 is a great car. I have a friend in Stuttgart who works for MB and has just collected his C63 estate company car. Coincidentally I have just collected my 507 estate. He was SO ENVIOUS! His opinion was that the 507 is a true classic, the last of the ‘real’ AMGs with a ridiculously big normally aspirated V8.
And I wholeheartedly agree with him!
The 205 is a great car, has great tech, more features, etc, etc. But it’s just an ‘off the shelf’ modern car, whereas the 507 is a classic muscle car, a real hairy chested AMG, and quite rare.
So as others have said, it’s really down to what you actually want out of the car. If absolute practicality is top of your list, the 205 would be better. If character and emotional appeal and pure hedonistic driving pleasure is important, the 507 would probably appeal more.
I bought a 507 Coupe (with only 24k on the clock) and loved it. But family needs made me hanker after a 507 estate, and they’re über rare, so when I saw a 23k miles, one owner estate for sale I weakened and swapped the Coupe for the estate. So now I’m on my second 507! But I hope and intended to keep this one a bit longer!