I just did my trainings run of Khitomer Accord (right after the Cure no less). The good news, We did it without any realy danger of failing. I know what to expect and how to beat the mission.
The kinda bad news. Bring enough time and a lot of nerves.
You will be facing endless waves of Borg drones on the ground. Really tricky placed nodes you have to take down. It's not that hard but takes a lot of time.
The rewards will be worth it though, lots of loot, several purple ones, the Assimilated Borg shield and a Borg Science BO.