Weber wrote very entertaining rules, and the back ground material if you divorce it from the game mechanics is very good. For the most part the interludes in the Stars at War bear no relationship to what would happen if you play the scenario. I found this to particularily jarring with the start of ISW3, where even role playing I could not achieve anything similar to what the interlude suggested happened. Based on my experience the interludes are written to generate overall an interesting story as you read through the book.
I got my start with Avalon Hill Board games, I don't find the rules in starfire either complex or well written, although again they are entertaining to read something that Squad leader is not. I do find them confusing and unclear because of statements like "a presser beam is for all intents and purposes a reverse polarity tractor beam." Worse by the end of the muddle over IS+3rdR+SM2+other publications finding a rule is a pain dans la derriere.
Still it works, and that is the key point. It works better when you have SFA to do a lot of the fiddle faddle for you. Also the newer rules have the advantage that they tend to be more organized, and well I find aspects of them too "balanced" or "bland" that is really a matter of personal taste and there are a number of things I like in Galactic Starfire, I just could never get the locals interested in a campaign because there was no GSFA program.