I'm enjoying my SL with a range of M lenses. It is on the limits of what I am prepared to carry around, to make cityscapes, with anything up to half a dozen lenses on a particularly indecisive day.
I am whether it would not be more sensible to get the zoom (Vario-Elmarit).
Looking at weight only, the Vario-Elmarit is the equivalent of about 4 M lenses. But it does give you AF and, perhaps more importantly for my type of subject matter, the ability to change focal length without changing lenses. The weight issue does not, however, end at the lens itself. Instead of making do with a table top tripod, which serves me well for 80% of what I need, I'd have to carry a heavier and more obtrusive tripod, adding another kg to the load, and being even more attention-seeking than the zoom.
I would also lose the ability to take widest aperture shots (although I often do so only to limit ISO, which can also be accomplished by the Vario-Elmarit's optical image stabilization).
Have I missed anything? What have been your real-world experiences?