User blog comment:Gracchus Mccarthe/A fair analysis of the Heavy Class:/@comment-24659969-20151203083557

Hold the Line: Increases damage and pierce while standing still.

This skill is most useful in situations that require little to no mobility and in narrow places. This is because the skill is only active while moving,  and the increased pierce will be more effective on long lines of enemies.

Wut? HtL active in full effect while standing still and have reduced effect when moving.

Brute Strength also reduces the penalty of speed when moving thru enemies. At level 4 or 6, you can push thru smaller enemies like nothing while bloaters slow a little. At level 16 or about that, bloaters are nothing. You can even pushback zombots, meaning if you move thru the bots they will be carried over with you. Maxed level, you might notice you start pushing back some bosses, this allows you to create some glitch by pushing them to glitched spots.

Things to know about Concussion: Every enemy has certain resistance and/or reduce-stun level to this skill. Starting from stalker has about 0.7 resistant and 0 reduce, means if your concussion only lasts 0.5, the 0.2 leftover would be the period they immune to your or ally stuns. This is to prevent perma-stun effect.

But bosses like savage zombie mech while not moving/rotating (ie:Shooting the machineguns) has full reduction aka can not be stunned. Savage devastator while enraged has bigger resistant and reduction level, from 0.9 resist and 0 reduce on normal to somewhere about 1.5 resist and 0.3 reduce while enraged, meaning with maxed concussion (1.7 seconds) would only result in 1.4s stun and 0.1 period where you can not stun them.

How do I know this? Play as Heavy, with maxed concussions and maxed black shockfield + masteries (aka 16.5 rps, 11 projectiles) in Mobile.