what i have found is if you spread them around they can do alot more damage, especially if your trukk gets blown up, since the mega armor can greatly slow your movement. the last game i played was against chaos space marines, i have my warboss in mega armor by himself, and then 2 squads of boyz with a nob each in mega armor. this spread my guys around especailly since he ripped through my boyz, who in effect just absorbed the damage while the nobs killed the CSMs. was a close game but it ended with me having my warboss, 8 boyz and 2 nobz left, while all he had was a tank, lol when i get back from class today if i have time i will post what each of us was using : )