Just finished the campaign, and I must say I'm impressed.
Many of the models are even better than what was in original FS2, and despite a much greater diversity you've still managed to keep a distinct style to each of the sides in the conflict. Looking at an AE warship you have no doubt it's EA and not GTVA terran etc., even though both are also clearly terran in origin. The GTVA terrans with their no fuss yet somehow elegant style of ship design, the EA with their blocky ships which one might think could've been cast in cement, the Vasudans with their rounded almost organic looking ships, and, of course, the Shivans with their spiky, evil looking vessels. Can't wait to see the ancients once they show up in a later release. And seriously, some of those shivan ships looked downright scary - not to mention the Nemesis, that thing just looks like a world of hurt just waiting to open up on you.
The story is good, and the mission design was for the most part excellent. Had a few minor gripes, but really nothing that in any way affects the enjoyment of the missions. They were all pretty challening, even at the easy setting I played it with this first time through, and brought along the story well. While the capships were powerful and deadly, they were never allowed to steal the scene from the player - it's always you who is the deciding factor in the missions, as it should be. Some missions required some fairly detailed wingman control, which cause me to blow them the first couple time I tried, but that just makes them even better... more fun having to think about what you order them to do that just hit c, 3, 9 and forget about them. So two thumbs up for the mission designers.
The tech room really shows how much attention to detail there has been. I spent a few hours just browsing all the new ships, weapons and intel before I even started flying. And the command briefing ani's are also good quality, and add to the 'feel' of playing not some random user made campaign, but more like a professional product.
There were some things that weren't perfect, of course. Like in the final mission, if you don't already know what's coming you have maybe a 5% chance of survival - I'd give the player another 20secs to run away before the gigas jumps in so that if he dies, it's cause he's an idiot and doesn't do as he's told. Also ran into a few minor bugs, like in 'Intangible Factors', if you click on the Pothoris icon in briefing, the destroyer is a Vesuvius class fighter. But honestly, who cares? The campaign and it's mods rock, and that's that.