I've used it - only two rolls were shot through it by the original owner before he went to digital. Got this setup basically new for a mere $499 (with the grip). According to my MZ-S manual, it's a magnesium alloy chassis... I am guessing titanium would be mighty expensive!!
Images:
Also have the TS-110 Timer. It's really a great setup with the grip. The AF is very fast, and as stated, some things might be better, and I've yet to really test mine with faster subjects, since I primarily shoot digital now. I am not sure about the back door being completely plastic, since it has two metal reinforcing bars on the inside, IIRC. It's currently at a local shop to act as the testing body for a lens issue I've got with an older AF Tokina 80-400, so I cannot confirm.
I am considering shooting some of the upcoming Civil War Reenactment with the MZ-S and the FA* 300/2.8 and FA* 80-200/2.8 with Ilford B/W film.
Regards,
Marc