I currently have a Konica 50mm F2. How good or bad is it compaired with a current Leica 50mm Cron. Can I make do with it or should I consider the Leica. And just to make things complicated do I need to consider the F1.5 from Cosina ooops Voigtlander as well since it costs even less? I also have a Tri-Elmar 49mm but at F4 it's a bit slow in some situations. Would appreciate your advice. Finally should it be chrome or black. <p> Thanks in advance.