The 35mm summicron has been a work horse in my modest stable of m mount lenses. It's my go to lens if I'm only going to be out with a one body / one lens kit, when I'm at home I tend to use this set up a lot. The only gripe I have with the 35mm summicron is that it isn't as fast as my 50mm summilux, which tends to be too long for crowded bars and restuarants. I spend a lot of time in dimly lit bars and restuarants and I've been considering trading in my 35mm summicron for a summilux (to get that additional stop) for a long time now. The price difference between the 35mm summicron and summilux (for the current versions) is pretty substantial. For those that have owned or do own both, do you feel that the price for that extra stop is worth it? Another reason for the potential change is that it would give me more flexible kit options (i.e. elmarit 21mm f2.8 paired with Summilux 35mm and the Summicron 75mm). Right now my 50mm summilux is the fastest lens I own so it always ends up in my travel kit, with the summicron 35mm being left at home b/c of space issues. With a 35mm summilux, I may be able to just use it and the 75mm summicron as a two lens travel kit. Any comments or input is greatly appreciated.