This is an early review, based on our first play-through. I plan to post another one once I have several games under my belt -- and I guarantee, that is going to happen, because we had fun.
I hesitate to describe TI4 in terms of TI3, because it's been revamped from the ground up. The changes to the strategy cards and voting rules alone are so fundamental that they don't track to any comparable expansion/rule/variant/etc. from TI3. Every strategy card finally feels useful. Nothing sat for more than one turn throughout our entire game, because everyone wanted everything.
We ran a five-player game: Sol, Xxcha, Nekro, Naalu, and Arborec. I was Sol, and I was fortunate enough to draw the Flanking Speed action card on Turn 2, and then rush to Mecatol Rex, Imperial strategy card in hand. This introduced voting, which was the first eye-opening change. Voting matters. In TI3, Assembly was one of those cards that you usually waited until it had a few trade goods on unless you had a good reason, and half of the time, the agendas themselves were pretty "meh." Not here. We got passionate about these votes, with everyone sort of set against me (since I was in the lead), but also not wanting to exhaust their planets unnecessarily. If you want a behind-the-scenes peek at this, here you go. (Warning: Potty language.)
Sure, we were screaming at each other, but laughing and enjoying it because it was refreshing to actually care about politics. And when the others banded against me, I knew I couldn't hold out, so I used careful action card learners test nsw play to slip away from Mecatol Rex and reestablish bulkheads in other systems. Meanwhile, Nekro built up to an insane fleet size, Xxcha and Naalu spearheaded the "kill Sol" movement, and Arborec quietly grabbed tech-specialty planets, trying to fly under the radar. Everything culminated in utter chaos.
My point is that it felt like there were just as many ways to race to victory, but at the same time there was no doubt that holding Mecatol Rex was the most straightforward. (Yes, Mecatol Rex has become the true center of Twilight Imperium, not just a side quest.) Unfortunately, it paints a heck of a target on your back. With the loss of transfer actions (which had long been used to get a "free move, then produce" instead of actually transferring), it felt like command tokens were scarcer and thus more meaningful. It took a bit more effort to get your fleets into place, which meant that other players had a bit more time to figure out what you were doing and try to adapt to it or counter it. And this isn't a bad thing! Not only did it make things feel more tactical, but each round felt shorter (never "dragged out") and each new public objective just got us more excited. I'm glad that we didn't house-rule transfer actions back in, and recommend trying it without them; it does play well with just the three types of actions (tactical, strategic, component).