I mean, if the colo'S supposed to replace the reaver, why not giving it the mulltiple beams attack with like a 80-90 damage. It could go to a mineral line and kill 4,5 workers in one shot. what do you think guys?

The Colossus in the latest round of balance has had it's damage increased, with its attack speed decreased a bit, giving it some more burst. With a couple of these on the field, it is quite effective at decimating armies of light armor units.