After having actually tried TITANS I must admit that it does tickle that old TotalA itch something fierce. The maps are still rather small (as they are spherical) perceptively, even though the actual space is quite large. The new units in TITANS really help shave off some of the issues with the unit scarcity, and the new Tesla unit coupled with changes to artillery units makes positioning, ambushes and devastation possible and helps defeat a simple blob tactic.
I'm still extremely disappointed with stationary defenses being excessively weak both in HP and in damage dealt. AA works just fine for the most part and provides adequate anti-air coverage, but land based defense towers are laughably weak and are mostly just a force multiplier when defending your base. You CANNOT rely on them. Perhaps if you also build walls, I've not yet tried this, but theoretically, the tall towers should be able to fire over the walls while preventing return fire from the approaching enemy.
Orbital combat is still something of an afterthought, but one of the titans is designed with orbital invasion in mind (it's a space battleship, neat!) and the new Helios unit allows for a solid foothold to be made even on a heavily orbitally defended planet since it's a mobile teleporter junction. You could land a small force with builders included on a planet with a strong orbital defense cover, but weak land forces and make a foothold. Also neat.
Overall, I honestly think it's a genuinely good game at this point. It also runs a HECK of a lot better than it used to, and I can now run the game on Uber settings with full AA and 175% superscaling without so much as a hitch in framerate. It still suffers intermittent crashing during mapgen, but the game itself has never crashed on me.
My experiences are solely from skirmish against the AI. I have NOT tried the SP campaign as that really doesn't interest me much.
All that said, I still think Uber are among the worst when it comes to PR and I genuinely think Titans should've been a free upgrade to everyone, because it does make PA a complete package. Without the new units, the balance is still utterly off. That said, I can understand it wasn't financially viable to do so, but man, PA just isn't good without Titans.