[Brightcolours]

It is not about the artistic value of them. It shows that the lens is capable even at f4 to make fine photos. Not everything is about MTF border measurements.

[Klaus]

I see soft corners and a mediocre bokeh.

[Brightcolours]

And how are the corner with that Oly @ f2, Klaus? The bokeh of that Nikkor is more than acceptable.

[davidmanze]

Very impressive how many good choices there are in MFT-land (except for equivalence-parrots).

  The wonderful thing about being a full frame user is you don't have to go there whatsoever ........ 
    ... which leaves your parrot free to squawk "who's a pretty boy then?"....

[Klaus]

And how are the corner with that Oly @ f2, Klaus? The bokeh of that Nikkor is more than acceptable.

And why should you buy a 12-45mm for bokeh shots?
There's the Oly 45/1.2 or Voigtlander 42.5/0.95 for this.

The Oly 12-45/4 plus 45/1.2 are still more light-weight combined than that Nikkor alone. ;-)

[mst]

Well, you won't impress anyone with a rather dismal Nikkor 24-120mm ;-) even although it may have an effective f/4.

Depends on what one needs to see in an image to be impressed. If it is optical perfection, from high sharpness to low distortion, CAs and vignetting to field curvature to smooth bokeh, then I can't name a single standard zoom that is impressive.

Fact is, though: even a dismal Nikkor 24-120 VR offers creative choices that are simply not available to future owners of the 12-45 Pro. Results that are potentially impressive because of the relatively shallow DOF in combination with the chosen topic, composition and background are possible with the Nikkor, but not the Oly.

For me, having that choice if required is important. For others it may not.

[Brightcolours]

And how are the corner with that Oly @ f2, Klaus? The bokeh of that Nikkor is more than acceptable.

And why should you buy a 12-45mm for bokeh shots?
There's the Oly 45/1.2 or Voigtlander 42.5/0.95 for this.

The Oly 12-45/4 plus 45/1.2 are still more light-weight combined than that Nikkor alone. ;-)

If you want NO flexibility in DOF, why not ditch MFT altogether and just make do with a cellphone?

As you can see from the Nikkor 24-120mm f4 VR shots, you can get quite a bit of subject separation over the entire 24-120mm range when needed. So that answers your question enough. 

Of course, there are people who are happy to make do with the FF equivalent of 24-90mm f8, and for those the Only seems quite neat indeed. But why disparage others, who do see the value of more DOF flexibility than FF f8 over that range can offer?

[mst]

And why should you buy a 12-45mm for bokeh shots?
There's the Oly 45/1.2 or Voigtlander 42.5/0.95 for this.

Well, for any aspect of a zoom it will always be easy to find a prime that can do that one thing much better. Isn't it the basic idea behind a zoom to offer many options in just one lens with an acceptable amount of compromises (but still compromises)?

[goran h]

I think it is better not to be too locked up (or a fanboy) of any brand. I can see both the advantage and disadvantage in several systems, and I have no need to make down one system just because i am in another. I think we all know the mft sensor has less capacity for shallow DOF than systems with larger sensors, so I find it a bit tiresome to always here “that is just f8” (f11..etc) on a FF sensor” and miss to mention other aspects of a lens.
My main system is not MFT, but I use it for some special applications (nature, wildlife).
Still, the amount of lens choices in MFT-land is impressive (and several with excellent bokeh). And of course, in some situations it is an advantage to use a system with large sensor.

[Klaus]

Sure, MFT has always emphasized compact size/low weight (& low vignetting, homogenous resolution) and the obvious compromise is DoF.

All this didn't change in the last 12 years yet we are still having the same argument from FF users over and over again that this is beyond acceptable - for them.
Nobody forces you to buy into this system. It's all about choices. It seems as if FF users have problems with the thought.
I, for one, have no issues with the existence of FF gear yet I won't touch it privately.

So for my personal use cases (which are obviously not yours), the 12-45mm f/4 PRO is an interesting new option and I'm looking forward to taking it for a ride.