The D'Kora is, actually, legitimately awesome if you manage to get it.
I've fought it, and it is very, VERY impressive. Can easily take on 2:1 odds, and can hold it's own against 3:1. After that, it can die.
Tips for fighting: Do NOT follow directly behind it. That EMP burst is nasty. At the same time, it can only hit a very narrow range behind it, so dodge to the side and it'll probably miss you entirely. You're a sitting duck if it hits you though, worse when the ship dumps warp plasma at the same time.
That burst fire will take down your shields if you don't reinforce them quickly, but that's not the real danger. The real danger is the missile barrage that comes afterwards. It can and will take down a ship with 40k hull very, VERY quickly.
It's very tanky, but fights more like an escort.
Also, the bridge is stupid small for some reason.