No problem Amin -- I just have given in too often, only to sell later. I used to have the 50mm f/1.2 M-Hexanon, and while it was really beautiful, it was just like an original summilux with another half click on the aperture ring. The difference was not huge. I did test. Here are the 50mm f/1.2 Hexanon at f/1.2, and the 50mm Summilux ASPH at f/1.4:
Not something that makes a HUGE difference. In the crops, however, the Summilux ASPH was much sharper. It is also smaller and lighter. I think this is a familiar pattern with super speed lenses (in most cases), you may get another half stop, but it will not give you much real benefit photographically, but it will add a lot to bulk and cost. Generally of course...there are exceptions and lenses that are truly worth their speed, but they are indeed the exceptions. I don't know about the 50/1.2 AIS, but maybe it is one of the exceptions.