Good stuff and completely agreed, the game is great!
I still haven't gotten round to finishing my readthrough of the core rules so I never realised that Chigusa Corp was included as one of the corporations! Yay for more AVP content sneaking in there!
As someone who's brand new to the world of tabletop rpg's I can confirm that this is a really great entry point. The rules are straightforward and easy to learn (though you'll certainly want to have a copy of them on hand for the more specific situations you might come across like a room being engulfed in fire for example), and it does a really great job of recreating the atmosphere of the movies.
I can't speak first-hand to the replayability of the scenarios since I've only played through Chariots once and am currently halfway through a playthrough of Destroyer of Worlds, but while you're certainly going to have some things "spoiled" for you by virtue of already having played them before it does seem like there are enough elements that can change pretty drastically to make other playthroughs unique.
Like Ridgetop metioned, mine and his characters teamed up in our playthrough, but he said that on a previous go where Hicks was playing the same character as me they were trying to kill each other. So even just having different people playing is going to make things go a lot differently than they might have in a previous session. Not to mention the dice rolls, on which so much of the game hinges.
Either way I think it's a pretty darn fantastic game and I'm definitely glad I took the plunge and bought it!