Not a fan of tech because I really don’t think that the whole tech thing was either conceived of nor playtested properly.
Either put it in the victory path and playtest it thoroughly, or take it out, I say. It’s worth noting that most players opt to play no tech precisely because it’s the least appealing feature of the game.
The sad fact of the matter is that teching regularly will lose you most games (due to the income not being spent on units) and hand you a near-effortless victory in a small percentage thereof. Both of these qualities detract from the main positives of A&A, which is a reasonably balanced intellectual strategy game with some - but not an overwhelming - element of risk.
Tech is not balanced (give super subs to Russia and Japan and tell me which one gets more benefit) and it diminishes the intellectual aspect of the game, replacing it with more random number generation. Not conducive to having fun, IMO.