Apparently, Momentum is not V-shaped at all. Check out the description of the sound signature in the following link. The quote was taken from second paragraph from the top:
"...Also, on both headphones, the treble above 3kHz is a little too rolled-off..."
HP50 will have a brighter, more neutral sound with more midrange and treble presence than Momentum v2 has. So HP50 should be a more balanced, better all-arounder.
I do agree regarding resolving capabilities of the HP50 - they are very high. HP50 is one of the most resolving headphones at their price range, easily. Yet, what I love about HP50 is that it is able to sound highly detailed, yet also buttery smooth and completely free of any harshness. Not many headphones can achieve this - most either lack resolution or sound harsh or bright in some way. HP50 is likely the most tonally balanced headphone I've ever heard.