I use both. Rangefinder for street, casual, and quiet shooting. SLR for fast, accurate, flash, portrait and telephoto. They are tools, I like having both. I could use flash on my rangefinders too, but I'm lazy and use the TTL on my nikons (F4 and FM3A). Neither of my rangefinders (Oly 35RD and Mamiya 6MF) do TTL.