I (re-)read up upon the blood axe, and it is especially good against mercs, because TU returned depend on the enemies bio resistance as well, and mercs have bad bio resists at 125%.
I do get the Scarab though which is probably the only codex craft that is viable until the late game.
And while I used the Shadowbat when playing gray I have to say that all codex craft have issues as transporters. Especially now that windows are a thing. No doubt that the Shadowbat is good, and it stands out among the codex craft with decent speed, loadout and not completly terrible layout. But I'd rather have a Deliverator ASAP.
I just got the Devastator, and it has a pretty amazing floorplan. My only gripe is that the elevators are not accessible diagonally (at least from one tile, not sure I tried the other), but that is a pretty minor issue.
12 gals, 5 exits (2 doors in the front, 2 elevators and a ramp in the back, which for once is protected by the back of the ship), 4 missiles slots (so I only use it to attack ships if I have to...) and it is fast (4500). But then, it is the endgame bomber, so it better be good.
I still use the Thunderhorse for most missions, as I can bring 24 people, but for missions where enemies like to throw grenades into the open roof or fire something explosive at the ramps I use the Devastator instead (and used to use the Deliverator, probably the longest serving Troop Transport, as it was also my go to craft for space missions and is now replacing the Drakkar in another base, that I am not very fond of).