The big reason for going to per-planet turrets was to eliminate the one big chokepoint.
And guess what... that failed. It's still the best defense strategy. The AI still has to be strong enough to beat that strong point... and will always be until all defenses "ressources" are limited by planets and not per galaxy. "Thankfully" some of the per-galaxy capped defenses are grossly overpowered - enabling multiple worlds to be protected. But, let's face it... there is absolutely no way that a chokepoint will ever become the worst strategy, ever. That's kind of the definition of a chokepoint.
If you had said that the chokepoint's power is comparatively "lower" compared to "regular planet" defenses before that change, I'd agree... yet the problem would also have been solved by reducing the quantity & power of per-galaxy defenses, or having the AI spread it's attacks more often. Or having the AI multiply its attacks when fighting a single choke point (that has been done if I remember well). So basically it never was "the solution" to accomplish that goal in the first place... just "one" amongst many possibilities.
However, I try to find what was lost / gained, I find the following:
- simplified beachhead made SF and threat mostly irrelevant.
- higher defence on all planets made it so threat delays more their attacks compared to before
- higher defense on chokepoint means the AI has to be made EVEN larger than before.
- higher micro-management.
None of that is particularly fun to me past seeing hybrids suiciding on beachheads during one hour or two. Then again, matter of taste ? And the AI is now getting ludicrous amount of ships at higher level which matter little because the efficiency of defending is so high. Which again, forced the game design to put "low" amount of scrap for the recycling and created a bunch of other issues (lag, carriers quantity, high number of starship, problem with caps of "parasited" units...). Would the other solutions have those effects ? Probably would have had other side effects, yeah. Still I think that a better solution than this was just waiting to be found.
About the rest of your post...
I'm sorry, but there is no link in that change and the consequences you are speaking of.
- Energy management could have been tweaked to matter in other ways.
- Game difficulty is a direct consequence of giving more spawns / mechanics to the AI. The amount of defense that the player's got is irrelevant - if you give the AI 5 times what the player can handle, he'll lose, whether the player has 10 or 100 turrets.
- as said above, relative difficulty of defending "standard" worlds compared to "chokepoint" worlds could have been solved in different ways.
Last, matter of taste. I find that having the same copy pasted defenses all over different worlds & beachheads does not really offer variety. Since it's mostly copy / pasted. Also, I hate micro-management. Before that change, I could not put the same defenses on all worlds - and had to handpick a few hundreds turrets to chosen chokepoints. Guess which feels like it has more variety & fun to me
.
So... I do understand why it was chosen - and why it pleases some, but I'd have
liked a solution based on "'let's rebalance stuff" instead of "MOAR STUFF".