Rise is a fast-paced game, yes, but it's also quite a lot deeper than Sins.
Man, what are you smoking??? It's "deep" only in the sense there is more stages. Might as well talk about Empire Earth II if that's the kind of mindless "deep" game play people want. I think there will always be some fast-twitch RTS players that don't "get" Sins. Speed does not equate to strategy.
Let's see. Rise has 22 different unit types as opposed to SoaSE's 10 (or 12 if you include combat utility vessels separately.) The combat system, while simple, is still more varied than in Sins - it has directional (flank and rear) attacks, formations, variable targeting priorities, garrisoning and entrenchment. There are meaningful infiltration and sabotage units (no, Timed Explosives doesn't count.)
Rise has more terrain features (location of resources actually matters), and placement of cities and buildings needs more thought. The economy is more varied, and needs more consideration than the simple payoff speed in Sins. Racing for Wonders adds spice to strategies.
Those are the primary differences in content. I purposely didn't mention normal buildings or individual units, because those are really just fluff and arguably not that important to gameplay.
Pacing and the tech trees are special cases. While it could be argued that the tech trees in both games are just incremental upgrades at heart with occasional new units and buildings, the "era" system in Rise results in far superior pacing. Each new era adds some new features and shifts management focus; you'll also be developing non-frontier cities as the game progresses. There's always something to do, and the focus of actions shifts between eras. Sins starts slowly, has a good middle game but not so good late game.
Bottom line? Yes, Rise is deeper.
Calling people capable of fast thinking something like "fast-twitch RTS players" is just silly. I'm a huge fan of Master of Orion (2), Dominions and Space Empires, but I can also appreciate a good RTS like Starcraft, Total Annihilation, Rise of Nations or Company of Heroes. I do agree with you that a fast speed does not equal strategy, but a slow speed also does not equal strategy.
And how to ensure that game speed and length are good for everyone? Speed controls, research cost options, accelerated start, victory conditions.
