One question that just hit me is how the loading system works in the tank. There's no autoloader (...in the prototype), but it still uses the same 125 mm ammunition as the T-72 uses. The fact that it comes in two separate parts seems to me like it would roughly halve the rate-of-fire (because the loader has to make two trips).
Moro-ever, the ammunition storage is literally the same as on the M-48 which is configured for single-piece 105 mm shells.
Also, another observation I made as I was looking through the photos from the Military.ir walkaround done on Army Day 2009 (or was it 2010), was that the TC doesn't appear to have any actual controls. The DNNS-2 right in front of the commanders MG-cupola goes to the gunners controls right in front of the TC. It's also kind of odd that the gunner has two sets of controls, the power-traverse from the M-48, then the fire-control yoke below it. Also, the distance between the FC-yoke and the eyepiece looks a lot greater then a traditional torsos height. Maybe it belongs to the commander? That would make the configuration make even less sense though.
Also, i'm more convinced then ever that there are two relatively distinct Z-1 prototypes. The 125 mm armed model (the one we've been seeing now) has a boxier turret, commanders cupola, and the occasionally, the DNSS-2A sight. The one armed with the 105 mm gun on the other hand has a turret whose bottom rear surface slopes up instead of just going parallel to the top. Some other features like ventilators, wind sensors, and maybe even a LWR or something seem to be interchangeable to a degree.
Lastly, look at all that deadspace in front of the gunnders control, that is some thin armor if you compare it to the main-gun mount to the left.
One overwhelming feeling I get looking through these pictures and making these observations is that it just confirms the belief that this prototype was only ever that, a prototype. It was slapped together to see what would work and what didn't.