Russian Consulate is just twice as long as the other CM missions. It has twice as many rooms with a lot of enemies in each room. Each room has rushing shotgunners, and healers, and armored Tanks.
Also if you use MM and you get too far (beyond the computer room) and people quit then new people spawn at the beginning and the computer room door is shut and doesn't open. The only thing we could figure out how to do is to wipe while the new people were standing next to the door, then they spawn in with you.
I was MM that mission and we got stuck on the stairs down to the panic room, the rest wasn't actually too bad.
2 of the randoms left, and Grim and Wiped came to save me. They did get stuck at that door but they were able to mobile cover glitch their way through it.