Okay, so, very new here. Played in Beta, took a break, back again. I'm trying to decide what to stick my engineer and tac officer in for my Tier 4 ship. I'm definitely going escort for both- if I decide on a cruiser later I have the odyssey to fall back on, and may unlock the Excelsior Retrofit for handy transwarpability either way.
So, escorts: I saw on the archived forums this has been done to death: As far as I could understand the wisdom was Sci ensign is slightly more useful than Eng ensign, but that sci consoles are less useful- but all that was before shield consoles suddenly became science. Has the balance of power shifted? Does Engy go one way and tac the other? I'll probably go one on one and the other on the other so I get to try both, but which is which? Inquiring minds want to know. For what it's worth I'll probably go cannon for the extra pew pew pew DPS, and am probably going to go dps as a simple role until I get the strategies and tactics down.
I run a Multi-Vector, and I like the setup. I can tear through nearly anything, and I have enough self-heals to survive for a short while under direct assault.
As for which is better than the other, I cannot say for certain. I PvP 1v1 semi-regularly, and I have yet to officially lose a single match, 1v1 (I lose in teams all the time). The only ship to ever give me a run for my money was the fleet escort, because he had so many freekin' heals, I was having a hard time keeping up with it.
Regarding making an escort tough, my old Fleet Escort build (admittedly with an engineer) was pretty tanky. Being able to run EP2S 1 back to back and having RSP1 as your "Oh crap!" button is handy, and I used science team 1 and hazard emitters 2 to cover heals. I didn't find the Advanced Escort (but other builds than the one I used may be) as durable, but on the other hand it has an easier time keeping cannons on target in duels with BoPs etc.