I have tried both and it really boils down to personal preference and your inclination towards crazy hone addiction.
The Chosera 10k is overpriced in my opinion. It does a good job after the Chosera 5k and leaves a level of polish that is acceptable but not perfect. There are, in my opinion, better polishers out there. Naniwa superstone, or speciality, are better in that regard. The speciality 8k and 10k are a recipe for black liquid mercury polish free of scratches under the 10x loupe if you are capable of it, at a portion of the cost.
The kitayama 8k does hold itself surprisingly well in that regard, too. And so do the Shapton glass stone HC 8k (grey) for high carbon and the glass stone 8k HR (white) for stainless, too (note, the grey one feels nicer, the white one is the better overall stone).
Feel: speciality stones are soft and can be cut into. Glass Stones are not for everybody as they feel very hard and without much feedback. The kitayama feels nice. The Chosera 10k feels really good, actually
Now for the junpaku 8k, it does a nice job as well. So dont expect any surprises from going past it if youre not planning to shave off of it