I have the D-lux 3, and if I shot more digital, I would upgrade. The 4 has answered almost all of the things that I don't particularly like about the 3. If you don't need shallow DOF, and you want a camera that will almost, but not quite, fit in a pack of cigarettes, the D-lux is a fantastic choice. Has the 4 improved the fiddly manual focus issues from the 3?