I think they may be missing something in the Stormtrooper's Starting Aptitudes. I looked at the cost of his characteristic and skills buys, and what Talents he can get.
He seems to lean really toward assault/melee than assault/shooting, can not get more weapon training apart from las and low-tech (they get Arms master, but that's it), they are oriented toward the one shot, massive damage more than the multi-attack, moderate damage the Guardsmen go for, but they seems to be costy to get characteristic advancements, except for WS being the only one I saw costing 100/250/500/750. Was it a way to maybe balance they fact they start with the Stormtrooper Carapace and hot-shot lasgun?
For me, they seems to be a specialty that's going to be slow to expand and get better.