Compared to the Vasari and Advent, their abilities just seem so sub-par or unimpressive to me.
I would argue that TEC capital ships actually have the strongest ultimate abilities...as has been pointing out numerous times, the biggest problem is getting your TEC caps to that point...
In my opinion, the greatest weakness of TEC caps is not the ships themselves, but the inability to protect them...Repulsion+TK push or overseers+Jam Weapons are fantastic at keeping caps alive...TEC simply don't have anything comparable at their disposal...sure, early game those hoshikos and power repair bays are nice, but later on Advent and Vasari are much better at protecting their caps....
To be honest, if you are going to pick a faction to have crappy low-level caps, TEC is the best choice...they have the strongest early game and while I'm not happy with their current outfit of abilities, the situation could be a lot worse...