Possibly they also might have paws instead of hoofs, but the leg geometry would be much akin to any other quadrupedal animal.
The larger body would also mean, that the base caloric needs of the hexa-limbic being would be much larger: An average soldier is seen as "75 kg" and is assigned 3000 kcal per day to upkeep him under a moderate workload. That makes pretty nicely 40 kcal/kg. A site about horse feeding told me, that just to keep a horse alive, it would need 143 kcal/kg. So, just summing both up and rounding down a bit for you don't need to sustain two brains, I estimate something in the area of 180 kcal/kg is the need to sustain these beings under some light to moderate workload. Which is about 4.5 times what a human needs per weight, and these beings are much heavier in addition? Taking something like a middle grounds, 160 kcal/kg sounds like a reasonable number too.
The additional space in the 'lower torso' between the middle and hind legs, however, it could mean that the whole 'upper torso' between the front limbs and the middle limbs could be devoted to having incredibly large lungs while the lower torso contains the digestive system, heart and blood cleaning systems.
Because these hexa-limbic beings would have entirely different needs, housing would look unfamiliar to quadro-limbic humans: chairs are more akin to a bench on which one rests the belly (instead of sitting on them), Beds might be unheard of (or more akin to the chairs), pillows would be in high demand.
Another of the needs the hexa-limbic beings would likely have is space: A human with 4 limbs can operate in any place comfortably, that offers space in the shape of a tube of 1 meter diameter and 2 meters height, give or take some for the size of the human. The Hexa-limbic beings would occupy most likely a box with a 2 by 1 meters floor and 2 meters height - which would seriously impact the design of cities and how some industries have to be handled.
Possibly the hexa-limbic beings can't manipulate things close to the floor very well for they can't bend down that much easily and crouching is not possible at all. So to operate things on the floor or pick them up, they most likely have to lay down - or they need to have longer arms, that almost reach to the ground.
Procreation of said beings might be a bit complicated: most quadruped animals have positions in which they go for this that would be pretty much hindered by a second torso sticking out orthogonal from where their shoulders are.