Here are the pure Kolinsky Eyeshadow brushes up for comparison.
The Shu brushes are clearly in a different price category, costing significantly more than the Hakuhodo brushes, however I find that I prefer them, regardless of price. The traits that I find in the Shu brushes that are lacking in the Hakuhodo brushes are fluffy tips and softer fibers. I don't really feel like these brushes are similar enough to be alternatives for each other, but they are both pure kolinsky eyeshadow brushes, so I felt that while shopping online, people may compare these together.
While Kolinsky fibers are generally known for having great 'spring' or bounce, I think the Hakuhodo brushes are too springy, bordering on stiff. I should clarify that I am not referring to the softness of the tips. The tips are wonderfully soft and non-scratchy on both brands. What I am referring to is how easily the fibers bend when pushed over.
The Hakuhodo brushes are much thinner than the Shu Uemura brushes (you can see this in the side view photo). The tips are in a much more chiseled shape as well. That means that there is not much 'tip' space, but it does allow great control with such a narrow tip. I find them difficult to use while blending due to the narrow chiseled tip, and the stiffness means I have to be quite careful to control the pressure I exert. The Hakuhodo 120 and 123 are very similar, with only a slight variation in size. I see no reason to buy both, they are so similar in size. If I had to pick between the two, I would choose the smaller one. On these brushes, the tips are very flat for the width; I prefer the less wide variation. I find the Hakuhodo brushes don't grab powder as easily.
The Shu 11 is my favorite brush out of all my eyeshadow brushes. The fibers are long with a wonderful amount of spring. The tips are never scratchy, and are fluffy enough to easily pick up powder and deposit it where you want to, instead of falling off the brush everywhere. The size is somewhat large for my eyelid space, but it is still narrow enough for me to place shadow where I want it, and it is large enough to blend with as well. This is a wonderful all purpose eyeshadow brush.
The Shu 15 brush is by the far the most expensive, and it's HUGE as far as eyeshadow brushes go. I use it for softening my eyeshadow above the crease. I find the brush wonderful for this purpose, but for the price, I am not sure it's worth the extra luxury. If you are on a budget, I would skip this brush. It's luxurious no doubt, but it's function does not really justify the cost.
If you like to pat your eyeshadow on using the fluffy tip of a brush, the Shu brushes will be much more agreeable. However, if using the flat side of the brush is more your style, I think the Hakuhodo brushes may work well. All of these brushes are rather large in size, so none of them will do well for detailed work. For that, both brands offer smaller brushes.
I believe one of the draws of Kolinsky fibers over Sable are that they are available in a longer length, allowing larger brushes. Thus, for smaller brushes, the cheaper Sable may perform as well.