Given what was said before about film tie-ins perhaps these were to co-incide with "Enemy at the Gates" in 1998/99. Not K&C's finest hour but still far ahead of anything else on the market at the time.
I live in a small apartment so I rotate displays and occasionally sell to make room for the new. Ususally it's like a dental extraction when having to offer sets for auction but in the case of Stalingrad I didn't really have sweet sorrow in the parting with those sets, which I sold in tranches (including my duplicates) in 2003 and 2004.
Strange that they did make the grade in the first place: at that time there was a fantastic 'Rough Riders' range, some good to excellent early DD and WS sets, or at least you could see the improvement with each release from those series. With Stalingrad there was no comparable feeling, and everything about them felt rushed: one of my RA02 sets came badly chipped (kindly bought by Bill Sager for a good price) and both of the RA05 tank killers I owned had come with some sort of unsightly resin leak/stain onto the white styrofoam, i.e. it wasn't just an isolated thing but was inherent to the model. One of my RA06 sets had a figure with a broken weapon too: it felt as if they had been thrown into their boxes to meet a box-office deadline.
Yes they're rare, yes they are an important part of military miniature history but no, I would not spend sleepless nights shedding tears if I never saw them again.