I support this issue. I would formulate as "Player's upgrades are confusing too (not as much as AI upgrades, but still)." I don't fully agree with your vision, Chris, when you say "AI upgrades go; Player's upgrades stay" because of different confusion level (even if I agree, there is a difference).
I also support this solution:
transform ship types as they are upgraded. Like: the Missile Frigate and the Grenade Launcher are two kind of ships the AI can have; the Human players cannot have the Grenade Launcher directly but can K-buy an upgrade to
transform (both technically and visually) their missile frigates into grenade launchers.
I already brought the "Heart of the Swarm" method of simply and clearly making twisting unit upgrades. (Even if SC2 also do small +1 upgrades.) And it perfectly joins my visions of things to answer that fine question of our fine fellow:
Though one question is, what happens if more than one upgrade is chosen for a ship? Or is that not possible, and it's just one upgrade at a time for a ship type?
I wish (and I proposed that since the beginning of that "upgrade" idea) to see only few, twisting and mutually-exclusive upgrades. No commonly shared hp x2, small regen, jacketering, etc, and one ship can have only one of some upgrades (the zerglings gaining wings for a big visual and technical change is a perfect example).
Iterating on that, I can imagine a short "tree" for that: a basic unit can be transformed into another (which has identical stats but gains a twisting perk) which can then be transformed into yet another. That would form a short tree. Here is an example: the standard fighter can be transformed into a bulletproof fighter with a decent armor for a more "tanky brawler" twist or into a raider with the repulsion perk (and some speed boost). Let imagine I prefer the raider for some strategical reasons; I would be unable to get the bulletproof fighter for this game. But then I can upgrade my new raider further: I can give it cloaking and turn it into a raptor (the base stats of a fighter plus speed, repulsion and cloaking).
That kind of things would be displayed in the new technology UI as a very small tree of icons and branches (from the fighter, two branches go upward, one has a length of 1 and the other has a length of 2). I don't envision anything larger than three choices per ship and branches longer than 3. But maybe we could slightly develop things a bit (while avoiding overly complicated stuff). I can imagine branches of different trees ending on the same leaves. For example, the raider could become a teleport raider by gaining the teleport perk, and the teleport battlestation could become a teleport raider by gaining the repulsion perk. We can also imagine some sort of "diamond trees": something can become either a teleport battlestation or a parasite (reclamation), and both can become a teleporting leech by gaining the other perk. (Just one more example because I can: a basic tractor unit can gain cloaking by becoming an EtherJet or being retrofit as a bulkier unit and become a
Spire Tractor Platform, or a Widow Something by gaining paralyzing tractors.)
I'll be back with some coherent small trees (I'll call that a hedge ;P) based on AIW1 fleetships.