Btw Droid and anyone else confused, the Mephisto IS purple. (and the Asmodeus is green)
That being said, none of the warships are purple so I'd probably not use it.
As for the campaign:
My biggest beef is that it didn't feel like my presence was necessary.
In mission #1 the player doesn't do anything except fly around.
In mission #2 the player basically does nothing as well. The GTVA has what, 2 destroyers, a base and at least one Aeolus there and the Shivans only send a couple fighters and bombers at a time. The player gets orders to "take out the shivan beams" but both the Demon and the Ravana get murdered in short order so they don't even get the chance to use them. Then when the Kismat arrives the player can't hurt that thing either so the allies get their butts kicked and everyone leaves.
In mission #3 the Shivans again only send a few fighters, while the convoy has plenty of guns to take care of 'em. Then when the Lamia arrives, it's basically unstoppable except versus TM guys. I even tried taking out its weapon system and instead the Lamia targetted me and blasted me out of the water. So I defend for 20 minutes against some shivan fighters, but it's not really useful because the super shivan cruiser is going to waste half the convoy regardless of what I do and even if I wasn't there the multiple AAAfs, 30+ terran turrets and allied fighters could probably handle the few shivan fighters and bombers that do engage.
Basically what I'm saying is that I have something to do in each mission, but if I wasn't there I don't think the mission would turn out any different so my presence doesn't feel necessary on any level.
Hmmn . . . some of the dialogue was a bit odd, though understandable given I've written some goofy dialogue myself.
Also is the Lamia's main gun supposed to be able to target fighters because it blew me to pieces when I tried to "make a difference."