I haven't found a real use for the Ark yet other than it being some oversized... thing... with a huge fighterbay... I tried to launch an attack with it once but I ended up using it (read:
moving WALL) to defend the base against 4-5 frigate waves mixed up with destroyers and corvettes of all things.... always happens when I attack, I'm bad at preventing getting jumped on... well MS + battle asset to save the day when the going gets though, the beam cannons were a lifesaver.
I even had a nice Shuttle with 4 juggs that in the end didn't do a thing as the game ended other than being a Patcher dummy base.
My most recent game went better, I had a pair of Vortexes with different guns still refusing to obey orders but I managed to force them back to base... battle asset MS, Ark, a few carriers sitting around doing nothing on fire support (might as well put the sweepers and crappy machine guns to use), 30+ fighters of random classes and the two stubborn pricks kept the repeated capital ship swarms at bay thankfully. AND DAMMIT enemy MS isn't capturable waste my time building frigates for nothing.
Curiously one of the CPUs decided to send out his MS, building an SY while at it just to defend his last resource point... or maybe he was trying to attack another CPU with me smack in the middle, I have no idea why the MS was moved well away from the spawn point. "Okay, your carrier blocking the front door to my base is annoying and my fighters are taking too long and MS beam cannon for some reason isn't firing, so here's a present..." BOOOOM--- "The Complex match is terminated for CPU x"