I have built the 1:200 YUAN and the 1:200 SONG. I am now working on the 1:200 KILO. These kits are pretty straightforward. Although the instructions are somewhat lacking in my opinion, with only 50 or so parts, the order of construction should be no problem. I consider the quality of the models to be good. Having said that, these are the first models I have ever assembled. The hulls have good detail which shows the many free flood areas, access panels, and other hull openings. I'm not so sure I agree with the recommended colors. Bronco called out for "Engine Gray" for the topside color. I chose Flat Black instead.
The 1:200 scale doesn't seem common for ships, but if they make other submarine models in that scale, I will definitely get them and build them.
The only real criticisms I have are with the seam which joins the hulls. All of the models had a less than perfect seam. This would probably pose no problem for skilled modelers. I puttied and sanded to smooth things out along the length of the hulls. At the bow however, the seam is very close to the torpedo tubes. This area requires careful attention. The raised detail of the torpedo tubes can be easily removed when sanding if you are not careful. The hand rails for all three models are very delicate. I broke one of the rails on my first model and replaced it with 0.55mm stainless wire. I successfully removed them from the sprue and attached them to the sail on the next two models.
I hope this helps you in deciding whether to buy the kit or not.