I am pretty sure that my Mizuno is pretty much as handmade and as factory made as my shigefusas and my Heiji (all being 240 gyuto's). When that is said my Mizuno is from 2011. The knives all have their advantages and disadvantages. So I think it is as much a question about preference as it is about quality. I consider these to be very very close in perfomance with the Mizuno being quite a bit cheaper than the other two - at least where I come from.
By the way - I have a 5-6 year old Shigefusa 210 gyuto, and a 1 year old Shigefusa 240 gyuto. It might just be me who got unlucky but the newer 240 is not finished to the same leves as the old one. The choil was black (kurouchi like), the handle was a bit rougher and the edge not at the same level ootb. So the big succes of the Shigefusa knifes might come with a price that is not just measured in $$$. Something that might be worth noting if the OP is looing for a Shigefusa. It could be a good move to look for an "old" one!