A few problems with the design:
1. Shoot it in the head with a BFG and it becomes a mindless potato.
2. If it's knocked over, how is it going to get up?
3. Power. What's it powered by? Magfields can only get you so far.
4. It has too much firepower for its suggested usage (think russian tanks with like 20 guns). You'd need to cart along ammo, reducing speed and stuff we can move. Considering we spend most of our time either running or stealing, I'd remove some of the weapons and replace them with storage canisters, for carting samples on research missions and stolen goodies on assault missions.
5. Is the production cost worth it? Why not get a bunch of Sods to haul our crap instead?
((Most of these were already discussed.
1. Its head is as empty as a robobody's - the brain is in the chest. Shoot the head and it loses one of its support CPUs, it main visual sensors, and some auxiliary stuff like the medifoam dispenser's nozzle.
2. As a horse would, presumably - the legs aren't mounted on rigid axles, it uses a cybernetic body for a reason. Tuck one side's legs under, extend other side and twist torso to shift weight, lift up and go. Even the Big Dog can get up if knocked over.
3. Huge-ass (literally) generator in the rear torso powering the frame itself and all the energy weapons.
4. All energy weapons except for grenades, no ammo needed. Targeting assist CPUs mean it can engage as many targets as it has weapons simultaneously without much problem. Grenade compartment can be (and will be, on the R2) converted to storage compartment, and there is ample space for any kind of backpacks and other containers on the back.
5. It costs, in production and with equipment, about as much as 2.5 cyber-Sods. It has the carry weight capacity of two standard humanoids (using all of its legs for lift), and can easily outrun all of them. Given same tier of weaponry, it will also match them for firepower, and it's a far smaller target than two regular Sods. In a way, it's a pair of Sods condensed to essentials as one unit.
As for the "too many weapons" thing - it can't be given just "one" weapon. For sheer symmetry it must have at least the two laser rifles. The kinetic amp is both for use in melee and as an obstacle-breaching kinetic ram. The electrolaser is Anton's signature weapon, and it is not mounted in the head because it's overloaded with features as-is, so it goes into the tail - making it double as a melee-range electric whip. The grenade launchers are the only things I agree on being superfluous, but I wanted it to have some indirect-fire area-control capability, especially for use in case its power supply is damaged.))