I'm still torn between the Jem'Hadar escort and the Armitage.
For the Armitage, I'd say play the safe road and carry a couple different types of ships for your hangar, so you can switch them out based on what your role is, team make-up, and specific STF requirements.
That being said, I think the Armitage is the most flexible, whilst still remaining in the "pure damage" category. The bug is a bit squishy, rightfully so.
I like the MVAE for the LtC Sci which lets you use gravity well, and the Armitage for the hangar. I think I lean towards the Armitage more since the Hangar can be swaped easily between STFs since different fighters do different jobs better, and it also seems to be fairly resilient, the LtC engi can also be used for eject warp plasma.
Defiant retro with cloaking device. the cloak drop grants a 5 second ambush damage bonus of 15% to EVERYTHING that hits within those 5 seconds. So you'll have to be fairly close to make those alpha strikes count. you won't be easy to corner due to its agility, but evasive maneuvers always comes in handy. long story short, you gotta play the defiant retro as if it were a Bird of Prey minus the battle cloak with a bit of a tougher shell.