Yes, KH have improved in recent releases.
Having built both kits, there is no contest. The Zvezda kit is fantastic! Clean moldings, with precise engraved detail, excellent fit through out. The assembly sequence works! Breakdown of the airframe is sensible. The ejection seats are great representations of the K-36L, and appropriate weapons are included in the box.
Where-as the KH has soft engraved detail, fit is "okay" for the most part (the engine air inlets are not great) and airframe breakdown just doesn't make sense. The K-36 seats are a joke. There is an overabundence of weapons in the kit, but there are not many that are actually appropriate to the aircraft. Yes, the decal sheet is a travesty! Not only are the wing walk lines incorrect, there are several other major markings where 2 identical markings are provided instead of left/right. The red markings have no white backing and are translucent.
Generally speaking, the Zvezda kit was obviously well researched, and great care was taken in the production of the kit, including someone actually making it to ensure fit and finish. The KH kit is very "approximate" in construction, feels very "rushed", and obviously no one actually built the thing before releasing it. (If someone "did" build it, and they still released it, then KH should be ashamed!)
The Zvezda kit is a little jewel. KH? Not so much...