From the review:
• The aforementioned more accurate electronically-controlled shutter, with a top shutter speed double that of the Leica's at 1/2000th and with a faster flash sync.
(vertical metal shutters on my Nikons ceased to work when stored for a long time. The horiz. on my Leica is still working.)
• The ZI is lighter, about 4/5ths the weight of the Leica. I see this as an improvement; others might not.
(a heavier camera body w/ less vibrating shutter is more stable and shakes less when you are shutting 1/15 of a second. IME)
• It's not as expensive. I see this as an improvement too, although maybe it's not one either. (now it´s more expensive.)
>It has a swing-open back, with conventional film loading. Finally. The lack of a swing-open back, which is standard on virtually every other camera that is even remotely comparable, has always been one of the crowning idiosyncrasies of the original Leica M design. Even to the point that Leica duplicated it in the digital M8, which seemed perverse to me when I tried the M8. Even some of the diehards don't bother to defend this one.
(the original Nikon F has a similar Leica arrangement: remove part of the camera to load film. NOt very user friendly but... it gives quiet loading. Nobody mentions that but the convoluted leica loading is quiet).
• It has AE with exposure compensation.
(just like a Leica M7..)
I am still not convinced to pay 1.8k for this camera. I will pay this money on other photo gear but not the ZI. It´s a free world do as you wish.