Hi,
It might be of benefit to also ask people who have used both cameras rather then used one and read about the other. Regardles of what I own my rule of thumb is generally hesitate to make disparaging remarks about a camera unless I have first hand experience. In the small DV camera class and the price points involved I think it's more a decision of what you're willing to compromise. To me, every camera I've used in this category has one or more problems, so what problems matter less to me than others is the question I ask.
If you have the budget, PS Technik makes a 35mm adapter for the Z1.
Sony is "against" progressive because with 1080i 1MP CCDS progressive scan would burn up the chips. You're trading off actual 24P for more resolution. In practical visual terms, 6 times the resolution of regular DV. We took 1/6th of a Z1 HDV still and magnified it full screen. It was equivelant to a full screen DV image. And you have an LSI chip version of 24, 25 and 30"fps" look available instead of nothing.
The Z1 has 16:9 chips and cine gamma controls (3 presets), if that does the job for you.
Less compression on less resolution is not necessarily better than more compression on higher resolution. Z1 lays MPEG2 on tape, it doesn't capture MPEG2. A newly designed Sony HDV codec does that. It is not the DV codec.
Since Cineframe is DSP you're not dealing with shutter speeds, which allows you to go 1/15, 1/8 and 1/4.
Good luck