reason: the pets make quite the difference. tacklers, flankers, shield buffer, all at your disposal, depends on the situation. and they intercept plasma torps.
and the torp console makes lot of fun, especially on mirror event.
just calculate the raw damage numbers involving the skills and 2 photon consoles. its just plain huge chunk of numbers.
imo the best ship a fed can get (aside of box ships).
MVAE is just "meh". 2 dumb pets, doing nothing special nor useful.
TER aside of being famous on TV really nothing special. can be good in pvp to deliver a surprise and feel yourself being like a klingon.
I haven't flown the MVAE mainly because I don't like the looks nor the multi-vector mode with the current setup for Pet AI's, so I can't give an opinion about it.
However, the other two, I do own and fly. (Like you, I am waiting for my Fleet to get a T5 shipyard from the Fleet HEC.) They both have their strong and weak points.
The TER (read: Defiant) is a decent ship despite having the lower HP. The spike DPS from using the cloak in an Alpha Strike manner is usually good enough to drop the shield facing, allowing your weapons to beat on the hull much quicker. And it is a Universal console for the TER and Galaxy-X.
The HEC is a bigger ship and able to soak up a bit more damage. And the fighters can be a major advantage, especially the Elite Scorpions as their AI seems to be a bit better than the rest (they usually try to avoid the Core breaches and Singularity implosions). Only down side to this ship is that once you fire off the TPDS, you WILL Insta-Aggro everything you hit. At least that has been my experience with it.
But, the decision will eventually be your as you'll need to decide which of the three more suits your playing style.
OR think outside the box complete. Escorts don't rule the DPS race anymore, regardless of what you are told, especially now feds can get plasmonic leech consoles. The king of DPS is very likely the Jem'Hadar Dreadnought Carrier but that's lock box and costs about 70 million EC on the exchange. You can do pretty good DPS though, with a ton more tank, in a tac oddysey or a fleet Excelsior.... It's too easy for tacs to get hung up on the idea that they must fly escorts with all the folks claiming crusiers can't compete, but in my fleet we've learned that cruisers can indeed compete, it just costs more to set them up to be optimal.
Oh and yes, I mainly use my 2 tacs (LB Romulan and a human, both feds), and I mainly fly cruisers and dreadnoughts. There are folks in my fleet happily doing 15k dps in dreadnoughts without too much effort. You don't need crowd control on them as the crowd is dead before it becomes a problem.
Cue folks flaming me for suggesting that escorts aren't the ultimate ships for tacs...
Shhh...your giving away the secret. They will nerf the dreadnought before to long...LOL!
I love the dread with 7 beams a blazing and frigates flying around spamming anti-proton sweeps...lol