For me, watching these movies is certainly a nostalgia trip. It had been decades since I saw The Karate Kid II, and while it shows its age, it certainly reminded me of why I was so fascinated with Japan (even if the movie was shot in Hawaii--young me didn't know that). Connor kept referring to the grainy Columbia Pictures logos as "old graphics," but otherwise the boys seemed to enjoy them. certainly, there was a lot of crane kick practicing in my house for a while.
I plan on still subjecting the boys to Ghostbusters II. To me, it is almost a textbook case of how sequels tended to run in the 80s. That said, there were still come enjoyable parts in it (okay, maybe only a few). We will see if they still trust my judgement after that.