I actually prefer the look of the dark none zenons personally
My Gti has zenons my missus Gt tdi has normal but dark/tinted lenses both black cars and i much prefer the look of hers plus i drive both cars alot at night and honestly can't say i see the improvement of vision with Zenons plus if bulb goes in hers - simple cheap job where as with mine expensive nightmare!
If it was a simple swap id do it and sell my Gti zenon kit for sure but as said its tricky because no level control switch etc in the Gti