U3 was a bit disappointing..
When i fought him, it was totally different to some of the videos i have seen.
The crate part was ok.
The part before the claws come was normal (Stand back and unload with the Butterfly, which had like 15 or something firepower)
When his claws came out, i just shot him a bit with the striker, then tossed 2 incendiary grenades and then he died..
10 - Supply Depot (1)
13 - Barracks
15 - Marine (1)
16 - Orbital Command + Supply Depot (2)
16 @100% Marine (1) - Command Center (2)
21 - Bunker (1) + Barracks (2) (3)