On the matter of weight... I wrote before to someone on the topic and said that I find the light weight and thin geometry on the Itinomonn absolutely wonderful like a race bike or racecar. The slightly heavier weight and the more convex geometry of the Shige is more like a cruiser or sports sedan.
They are very different from one another, but I have to say that my favorite nakiri are the Itinomonn (original version, no experience with the stainless-clad version) and Shige (both KU and kitaeji). For a fast, quick job, the Itinomonn is great... but like a racecar, it's missing the "comfort factor". The Shige, on the other hand, is great for bigger or longer jobs, where you just get good momentum and you feel in the groove while performing well.
For me, anyways, there's a place for both ends of the spectrum in terms of weight, assuming good geometry and construction... which all 3 of your main choices have. But if you're going to just choose one, my suggestion is to decide what you value more: pure performance with a bit less "comfort" and "feel", or something that you can just keep going on forever because it feels right.
BTW, my wife who knows almost nothing about knives - and although she'll admit they feel different from one another, doesn't want to know much about them - much prefers the Shiges over any of the other ones I have. So I think there's something to the "comfort plus performance" vs "pure performance" thing.