The problem with X3 is that its manual is,in essence, the X2 manual with a few cut and pasted paragraphs to cover the X3 features.
X3 is sort of like Eve online without the annoying people, and an ability to save and go back to a previous point, which is good ;) The downside is that it is controlling thousands of ships in different systems all at once, firstly, as mentioned, the AI, at least outside of combat, is very simplistic (In fact, when you have fleets, whether you stay and watch a battle, or go to another system and let them fight it out WILL alter the outcome of that battle quite significantly), and secondly, this makes it a game that really was ahead of its time, my i7 loves it, my old Core 2 Duo was struggling after the Empire started getting big ;)
The hard part, I have always maintained, is starting the game, getting to a point where you have a financial backing capable of supporting some proper military incursions is a very long process, and many people get bored, it was designed to be sandbox, and the weakness of the campaign does highlight that to a degree, and is compounded by the huge error of the fact that they forgot to put gun objects on the final Xenon ship you face when they shipped the game, so the final battle is a joke
. I believe a fix may exist for that now, however.
Combat requires a LOT of jinking, you do practically spend half your combat time going sideways ,but I tend to wait until the local Police have engaged larger groups of Pirates and then join in.
Oh, and missiles are pretty useless in close combat, great for heavy ships, but once battle is entered, most missiles you shoot will be destroyed the second they leave the ship :(
That said, I enjoy X3, once you start building factories and owning small fleets, the game sort of changes from a simulator to an RTS in many ways, just wish there was better control options on the map screen for your ships.