Good. Marred by some strange VO choices and a complete lack of continuity (lose DS9, go back after finishing the mission to shop for STF gear- wait what?). But overall a far cry better than Skirmish or Cold Call, definitely in the same league of awesome as The Vault.
I thought that it was good. There was a nice mix of events that covered pretty much all of the bases. It had a little bit of NPC character development. It had some Diplomacy going on. It had a mad escape while under siege. It had a huge space battle to round it out.
I think the biggest problem with Second Wave is that we went into it with months of knowing the Dominion would be coming out of the wormhole. Half the mission is building up for an "Oh ****!" moment, but when they advertised the **** a year ago, there was no surprise, so the lead up ends up just being a delay.
I think for the next FE, the devs should keep the main enemy a tightly guarded secret, up to the day of the mission. If we'd actually gone in blind, it would have been a better mission.
Right now, we wouldn't know what's happening. We wouldn't know if this was the 2800, or a renewed invasion. We wouldn't know their objectives, we wouldn't know if there's more ships coming or if they've coordinated with old allies in the Alpha Quadrant.
We pretty much know all that, we knew it months ago, because Cryptic let us know too much about the series.