I'm not sure which SSI wargames you're referring to, but I'm of the opinion that games like Panzer General, Clash of Steel, Steel Panthers and Close Combat were the ones geared for casual play, while the more recent Gary Grigsby offerings such as this and War in the Pacific are the ones that are way more grognard-y and detail abundant.
Oh, the ones I had in mind are Great Naval Battles, Steel Panthers, Pacific War and Silent Hunter. I would even extend that to The Operational Art of War, given that Norm Koger was also a SSI guy (although TOAW was not published by SSI).
The striking thing in these games, for me, was that they stretched the technology available to provide what was then great complexity. Steel Panthers for example was light-years away from competition. Nowadays the bar is raised, though, so today one could even argue that, for example, Silent Hunter is a beers-and-pretzel game rather than a detailed simulation.