When talking about cow sizes in general it's like comparing apples to oranges because everyone has different types of cattle they breed for and different management practices as well that there is no "one size fits all" way to compare anymore. Go look at the various topics that have been discussed on frame size here and there is variable #1 right there for mature cow weight because breeding for bigger frame cows are going to result in heavier mature cows weights by default. Then the next big variable is management practices - how much for inputs are you giving your cattle as there are guys that don't creep feed or don't push feed to their cattle at all at any point of their development. I don't like to criticize how people run their operations, we all do what we feel works best for us but it's also no secret that fat sells too and there are plenty of way to pack on some pounds and make cattle look fleshy but when the fat melts off what are you going to find under that? Some cows of certain size just won't work in some environments or management practices, especially if they are going to require a lot of inputs to keep up a healthy condition. Doesn't mean they aren't good cattle, there is a market for just about anything out there but you gotta commit to what kind of animal you are aiming to raise and stick with it.