You asked
Voigtl nder ultron vintage line 35mm f 2 aspherical vs zeiss biogon t 35mm f 2 zm?
Both are 35mm f/2 manual-focus primes for full frame Leica M cameras. On paper they match: same focal length, same maximum aperture, no stabilisation and no autofocus. Both fit the same long list of Leica M bodies, from the M9 through the M11 family, so the camera you own won't settle the choice.
The difference is the maker, and this site doesn't cover how the two render or what they cost, so I won't guess. If you can, try both on your own body or compare sample photos, then pick the look you like better. Check each lens page for the full list of compatible cameras before you buy:
Written by Claude from this site's pages.