Go for it! The MZ-S is a great camera, and even better with the BG-10 grip.
Not so sure about the 360 flash, since the head doesn't swivel. I've been
using a Metz 40MZ-3 flash with my MZ-S, with good success.
The MZ-S focuses well in dim light, better than the D100 or S1 Pro. As for
noise, it's louder than a practically silent EOS-1V when focusing, but also
much less expensive. I don't find it too loud, and the focusing is
accurate. It's easy to switch it from automatically choosing a focus point
to using a preset focus point. The AF certainly seems accurate enough.
Lens-wise, I've been using almost all F or FA lenses, with the exception of
an old 500f8 mirror lens, and the in-focus indicator is handy with that one.
My everyday and short studio lens is the 28-70f4, and it's a handy
combination with the MZ-S. The 28-70f2.8 is quite a bit bulkier, but should
work well with it.
As for William's "film is dead" comment, I can't agree. Film and digital
have two different looks, and I prefer the look of film. Digital appears
sharp, but has soft detail. Film appears soft, but has clear detail.
Neither is perfect, nor is anything else in this world. Hope this is
helpful.
Pat White

