I've seen some discussions about advancing tech trees in Elemental in a manner not entirely unlike Galactic civilizations 2, civlization and other games.
It seems to me that the two of the big influenses on this game (The Sillmarilian and Master of Magic) didn't have tech advancement n this manner. (I could be wrong about MoM I haven't played it since 1995).
Tolkin's middle earth existed for thousands of years without any real improvement of technology
I think MoM was similar to Age of Wonders wherein you developed new and better magical abilities but your technological economic and industral abilities was (outside of magic) linked to an unchanging set of city developments. Ergo if the city of Townsville has building X it produces result Y. There wasn't a civilisation wide advancement from iron weapons to steel or from three field farming rotations to two field farming rotations (aside from magic).
Do you see a benefit from technology advancement system that work partially independantly from "social production"and magical advancement? If so is it only in customizability, or also in flavor and richness?
For me, I like to have lots of knobs to tweak but ancient civilizations with static technology is a staple of the genre that I think adds to the feel rather than detracts from it.