Hi Han,
The 35 Summilux pre-asph is a very good lens. It does suffer coma at wide open at the edges but other than that it sharp and has the summilux character. One of my favourite lenses. Compact and great handling. The titanium one has become a collectors item so it is pricey if mint.
By the way, I wouldnt sell the 35 Summicron Asph if I can help it

Hope that helps.
Cheers,
Paul