I have to admit that I haven't seen the loose remake of the first film, so I'm not sure if it devalues the first film now (probably not), but I know by rule of thumb that remakes of good films rarely hit the mark.
This collection takes me back to my childhood and my opinion of the films has slightly changed, but not negatively.
First of all, I want to say that there aren't any remarkable special features here and that's perhaps expected as we're talking about films that were originally released on VHS. The packaging of the films is nice, if simple, and this set is better value for money than the collection with only the first three core films as you get more for less here.
To get the fourth film out of the way first, The Next Karate Kid was wholly unnecessary and drove the stake into the series. Only Mr. Miyagi (Pat Morita) remains from the original series and the film is basically just a joke. It leans too far on being comical and the absence of, a by now far-from-kid, LaRusso (Macchio) is a loss.
The first film is essentially Rocky at a Karate tournament but with the slant of showing a bully getting his comeuppance and detailing a surrogate father-son relationship. Because it's the first of the series it is undoubtedly the definitive one. It's well made and holds well to this day.
I never originally liked Karate Kid II as it had more of a story (which I didn't care for as a young kid), but in my early 30s I think it's the most engrossing one and it even did the most well at the box office. The heroine here is the cutest of all the films, the backdrop is stunning, and it was great to see this story focus more on Mr. Miyagi.
Karate Kid III shows things running out of steam, but it caps the circle off nicely. In truth this is just Karate Kid I moulded slightly differently. We're back in America, back in a tournament, and this time we see a revenge story and the temporal breakdown of a relationship. I thought the main villains here were a bit wooden and not much goes on for the first hour. Plus the final fight is disappointing for a guy by now who is quite a seasoned Karate fighter. It's grace is that it beats the fourth film.
For little more than a fiver this is worth getting if you loved the old films, or if you want to show the kids that "it was better in them days."