I used a pre-ASPH 35mm Summilux as my standard lens for almost 25 years and then when the ASPH version came out thought I would really benefit from its improved performance. The ASPH lens IS a fantastic lens; but I missed the compactness of the older lens, light weight and how it handled. And although it can flare, I really liked its 'look' with slow films and overcast days - there isn't another lens like it.
Sold the ASPH and am a happy camper with another pre-ASPH version again. The ASPH was worth the try and for some people its their best lens - different people have different 'vision' for their photography.