The most disappointing part to me is that they used a small fountain pen nib. I'm not referring to the F/M/B size.
I'm saying the gold hood nib itself is rather small. Expensive fountain pens are characterized by one dominant factor.
The size of the gold nib itself (how big the piece of gold it is), and the diameter of the feed size (4mm/6mm/8mm/9mm).
Seems here that Montblanc used a very small gold nib, probably a 4mm to 6mm feed.
And it's just not a very special for the 25.000 Euros they want for this pen!
You wouldn't buy a chronograph for 25.000 Euro without a column wheel system.
I wouldn't buy a 100.000 Euro sports car without a double wishbone front suspension (although a lot of people who don't understand certain important aspects do this).
I find this pen to be a little strange because the price is not matched with the components.

Montblanc 4mm, 6mm, and 9mm feed from left to right. Notice the nibs go from regular sized, to large, to HUGE. A larger nib gives you a more flexible and bouncy writing experience. Thus, imagine the metal bodied pen, with its small and firm nib, if you were to write a long time with that and with short strokes, it'd feel tiresome and rough!