Would like to share something I've been thinking about. It seems that everyone complains about the massive use of air power (especially when the tech levels advance). One of the problems I have with the way tech advances are handled is that when a unit type goes up a level every unit of that type on the board goes up to the new level. It seems to me that it would make more sense (in the case of air, rockets, armor, anti-tank, anti-air), if only newly purchased units would be at that level. Hardly makes sense that the end of one month your air force is one type of plane and the next they have miraculously been transformed into a more advanced type. Currently I build as many units at the cheaper cost with the hope that tech advances will improve their value down the road. With the "you only get the new shiny stuff when it has been invented" paradigm, people would be forced to make the decision to build old level units or wait to the new level comes online. When newer levels come into being older types of units could still be rebuilt to the maximum level their current tech would allow, be used up in battle, or disbanded. Any thoughts?