Got to play two rounds of three player Quantum yesterday.
It was pretty good. It is a nice in that it is really easy to explain in five minutes, but has plenty of complex chains of actions you can do. When you get to use your entire fleet's set of special manuevers in sequence to pull off an important tactical repositioning, take out a bunch of enemy ship, or swoop in to drop an unexpected cube it feels really great. This grand moves being possible actually made the game play way faster than I had initially expected. We got two fairly back and forth games in about two hours. Playing with three players never seemed to devolve into the leader vs the other two, as happens sometimes. The victory condition of placing 5 cubes can be reached extremely quickly, so you kind of need to keep the pressure on both your opponents at all times so you can disrupt their plans while also trying to get some cubes down for yourself. Playing on the smaller board layouts also help with this.
There is a bunch of stuff in the game that just makes it feel really smart. The base mechanic of each ship being a dice where the number is how far it can move and also its attack power (with lower numbers being better) is genius. It lets you quickly look at the entire board and assess the whole situation without having to remember the values for different ship miniatures or anything like that. And the dice are big and beautiful and just feel great to roll.
I didn't mind that you roll dice quite a bit, since the bigger ships still win the majority of encounters so effective maneuvering is still gonna get you significantly better results.
I don't think it fills a 4x space game hole in a collection though, since it is extremely abstract. If you want that feeling of moving epic fleets around a board and building a massive empire you're still gonna need something like Eclipse or Twilight Imperium. But it is a fun game with plenty of decisions that can be done in 45 minutes.