[@Klomster] Actually, marines really aren't all that fast, in terms of reaction time. They've got higher quality sensory input than the average human, but nothing they get actually increases the speed at which they process that information. The only thing is training and conditioning, and that only gets you so far before you hit the physical limitations of relying on a biological sensory system, which humans are already pretty damn close to to begin with.

Ironically, given the fluff behind ogryns, they may actually have a better reaction time than marines. Ogryn brains never really 'devolved,' they just mutated to better meet different needs. They seem less intelligent because their brains are more geared towards survival than social pleasantries and basic skills like mathematics and grammar. However, that's actually in their favor, as it means their brains have adapted to filter out all the 'white noise' and focus only on what matters; survival, and by extension, processing information that's important to continuing it.

They also win in muscle density. They average 2.5 to 3 meters tall (that's 8'2" to nearly 10' for my fellow imperialst scum), without any kind of power suit. See, the weird thing about Ogryns is that, on a homeworld with nearly double earth's gravity, they got Bigger. Things don't get bigger when there's more gravity, they get more compact. That's why whales don't work well outside of the water, they need the buoyancy to keep their bodies from being crushed under their own weight.

Ogryns, on the other hand, were put somewhere they should have gotten smaller, and actually got even bigger. That means the need for sheer brute strength was so great, that somehow natural selection favored the largest, despite that extra bulk working against them. This next part is pretty math heavy, so I'm going to use a hider.


[hider=Math stuff for anyone who cares.]
So when a given body increases in size proportionately by doubling its height, its mass will increases by a factor of about eight, just by a purely mathematical sense. Given the size of the average Ogryn, assuming their weight in a standard Earth environment increased by Only that factor of eight, then halving their height of upwards of 10' would mean we're basing them on the average weight of a 5' man. So, the 'ideal' average weight for a middle aged man of 5' height is right around 110 lbs. That means the matching ogryn would weigh 880 lbs on Earth. Now, on their home planet, they would weigh twice that. Meaning, that all of their bulk has to be able to not just barely, but effectively and regularly support 1,960 lbs.
[/hider]


Meaning, an ogryns muscles have to be dense enough to heft around 2 tons of weight at all times, naked. As the average space marine only has to pack around 600 pounds naked, and both are required to perform under battlefield conditions, the Ogryn at only a couple feet taller would Have to have over double the muscle density of the average space marine.