The ability to change the speed of the game at will in a single player is the top of my wish list. I can fiddle with maps/settings/teams/etc to get a sufficient challenge, but some parts of the game are far too slow paced.
CityMan
It's easy to say that a mobile defense fleet or fighters are the counter. Most people have a mobile defense fleet, but it can't be everywhere at one time. Even having a lot of fighters doesn't make a difference if the siege spam fleet just runs away. The core problem is the fact that 20-30 siege ships can destroy a planet before your defensive fleet can respond. Once that planet is gone, the siege spam moves to the next planet and the next, completely ignoring the defenses. Once you
I completely agree that siege spam is a broken game dynamic. It's really obvious because it's a favorite AI tactic to mass siege, completely ignore defenses and kill the planet first. The planet is long dead before your defensive fleet has a chance to return. I don't think improving PJI's is the solution though. That would dramatically change the way the game is now and make it into a turtling match. Siege just needs to be made far more vulnerable to stationary defenses.