Just finished playing through and I have to say this is a significant improvement over the original release, which in itself was good quality.
First off the biggest single improvement for me was the Vishnan section of the campaign. The new skyboxes for this part (and outside of it) had to be one of the biggest gains in immersion factor for me and easily equalled the added immersion of the voice overs. The first release version of this was good but it just didn't pull me in enough to what was going on storywise, this time it properly hit the mark for me and was more clear.
New models where also very good, again the Vishnans were a big improvement along with the Sanctuary's forces and that previously ugly spacesuit!
Backstory is often missing in most of the campaigns I've played so far or is only lightly touched on as if it's an after thought. It was good to see this level of effort put in for Blue Planet (on your website and in game), it must have taken a large amount of time and I think it paid off bigtime as it added greatly to the setting of the campaign. It also shows the level of pride your team has for their work to put in so much effort to immerse players before they even get to playing the missions.
Changes in the dialogue along with voice overs also made it more clear of what was going on overall and as said by others the cutscenes were also greatly improved and played out much better,
especially the death of Bei's mother and sister.
Much better done in regards to camera positioning and direction this time around.
I played through with Fury's enhancements from the start (on medium difficulty) which did seem to make combat play better.
The Dragon swarm in the second earth patrol mission was a bit hairy to say the least. The mission where you protected the GTC Duke against the Demon had to be possibly the hardest part in the campaign for me (probably due to Fury's AI and the fact I only had 30% hull left at the start of it).
Last but not least the music. How much does a good soundtrack add to things. I think the music even in the first release was very good and certainly no worse than what we've heard on TV shows such as the recent Battlestar Galactica series. It really does compliment this campaign as much as the voice overs if not more. To me it is one of the strong points of AoA that really stands out. It's good to see other projects like Earth Defence for example making good use of their own in-house produced music.
So now for the criticisms and nitpicks.
The only problem I had with the voice was the command briefings from Captain Al'Faddil at the start of the campaign. Sometimes the speech dipped low enough it was inaudable in places.
I'm sure previously a Lilith used to attack the Sanctuary near the end of Universal Truth? Removing it made the mission seem a little less challenging and unfortunately kind of took the edge off of it.
Terran wingman built-in messages play in the first Vishnan flyable mission (The Great Preservers) if you order them to depart, I haven't tried similar orders outside of this Vishnan mission however, again minor as you can just leave the depart orders alone.
Wing reservation keys (function keys) weren't used much in most missions. Yes this is a very minor nitpick but I personally like to be able to bring a wing up quickly in battle and see what they're currently doing. It can help management (personally) if events change quickly during a mission and you need to see where allied wings are at a single press of a button and what they're doing.
Other than that it was a pleasure to play again. The obvious hard work put into the voice-overs and graphical enhancements have been well worth the wait and I'm now looking forward to playing War in Heaven when it's ready. Great work!