Blown away by the 16 55 f2.8! But not with XT20

So, I have been a Sony shooter since as far back as I could remember. I had mostly been using their Kit Zooms. Recently wanted to upgrade so decided to try the Zeiss 16 70 F4. I was not really impressed with it at all. Infact, it performed worse than my 16 50 Kit Lens under most circumstance. I had posted a thread here:

https://www.dpreview.com/forums/post/59723795

So, with the lens frustration, I decided to try Fuji with the XT20 & the 16 55 F2.8. I received it yesterday evening & have been playing with the combo. I must say, I am absolutely blown away by the Lens! It simply blows away the Sony Kit Lens (Obviously), but also the Zeiss 16 70. Not only that, it actually matches the Sigma 30mm 1.4 which is touted as the Sharpest Lens on the Sony E Mount. This Fuji lens is simply outstanding! Here are some samples comparing the Sigma Prime to the Fuji Zoom at f2.8. Now, keep in mind that the Sigma is stopped down from 1.4 to 2.8 while the Fuji Zoom is wide open!

Having said that, I am not that impressed with the XT20 though. If you look at the metadata of the above two images, you can see that while the Sony took the picture at ISO 100, the Fuji needed ISO 200 to achieve the same brightness level. So, at base ISO, the difference is exactly 1 Stop. And although I am still finding my way around this camera, it appears that at higher ISOs, the difference increases even more. Yesterday, I was just taking random pictures around the house in poor lighting & the Fuji was consistently needing 6400 - 12800 ISOs while the Sony was chugging along at 1600 ISO to achieve the same shutter speed. Don't quote me on this just yet, but the difference was so noticeable that I knew something was not right. I still need to test this under more controlled conditions.

Do you guys have any views on this issue?

Also noticed that the Fuji's auto exposure blows out the highlights in extreme cases. Whereas the Sony A6000's auto exposure maintains a better balance. Is there any way to show blown highlights on the Fuji? Sony has a Zebra setting that starts to flash the blown out areas in the viewfinder giving you a preemptive warning. I couldn't find that setting on the XT20.

Here is the same sunset shot with both the cameras. The Fuji seems to recover the shadows exceptionally well, but the Sony very easily recovers the highlights. Infact, I think I could have exposed the Sony higher by 0.5 - 1 stop & it still would have retained the highlights with better shadows. Having said that, the Sony tends to show a Green Tint on the recovered shadows & has pretty bad color noise that the Fuji simply does not have. Overall, I also liked the Fuji Colors better.

This is a pure test to see how we can push & pull highlights / shadows. Don't judge the pics.

Do share some tips / settings that you use to capture sunsets or other scenes with high contrast such as this: