I have a full set of silver hassy lenses and they are very sharp and contrasty. I have also not had any problem getting them overhauled and in the one instance that a lens needed repair (last spring) there was no problem getting the part required. There are T* silver lenses as well.
As with any lens, old or new a lenshade should always be used.
When I was out shooting with Les in the snow covered flat lands I shot several pics straight into the sun with my 50mm WA and had practically no flare and still great contrast.
People who say stay away from the silver lenses probably don't use them themselves and are just going on rumour or bias IMHO. I have not had any prints put side by side with mine from any non Hassy MF system that comes close to the razor sharpness and great contrast and tonal range of my old silver lenses. Zeiss glass is Zeiss glass, period.