Hi,
E-shutter on the IQ3100MP is even much slower, but many photographers still feel it is beneficial. It probably works well for small objects not moving very fast.
The GFX does have electronic first curtain and that makes it more general use.
If you make significant use of third party lenses, like T&S or technical cameras, the GFX would probably make a lot of sense.
A significant number of new lenses for the X1D are promised for 2018. That indicates that Hasselblad is really serious about the X-system.
It may also indicate a bit that mirrorless is where the future of MFD is.
Which one is better? That would be hard to say. Sensor is essentially same. It seems that Fujifilm is putting a lot of design effort in the GFX lenses. Hasselblad publishes real world MTF data for the X-lenses and last time I checked they were very good.
It may be that it matters little which one is better. They are probably very good and it takes a lot of care to get maximum performance from either. An don't forget, diffraction limit is always around and it is essentially the same for any lens on the planet.
Best regards
Erik
Could not disagree more on the E shutter on the GFX. I personally use it all the time outdoors in windy conditions. It's just like the E shutter on the IQ3100. You have to be on a tripod for sure as any movement by the photographer will be easily seen, but moving subject matter unless the winds are blowing 20mph or faster are fine. You can't use it on a moving person, or car or any object moving at a high rate of speed across the entire sensor. Leaves OK I guess as they are individually not taking up a lot of sensor space.
E Shutter on both cameras and now on the D850 work all about the same IMO. Not for hand holding, but on tripod out outdoor conditions, fine.
I guess since you have two varied opinions, you will need to demo both cameras to see, but for me the E shutter is used daily.
Paul Caldwell