I would personally go for MZ-30/ZX-30 for two reasons: ability to take multi-exposure pictures and diopter correction. ZX-10 has a panorama function and power zoom, but somehow I feel they're not as useful.
there are so many pentax auto-focus (compared to the Nikons) and meanwhile it seems the Pentax autofocus seem quite a lot fragile...
i will verify for the mz-30
thx!
I will finally acquire a Pentax Mz-30 with a mid range 28-90mm + a bag for 30$, unless the transaction turns out bad.
So the investment won't hurt in case the Pentax body stops working.