When my cousin first got me into handloading decades ago, I started out doing it standing. Over the years, I've tried doing it in the sitting position a few different times, never worked for me. I've tried chairs and stools of different heights. Even adopted a lower bench for experimental purposes. When I'm sitting, it seems that my movements are more restricted. Standing, I have more freedom of movement. Before I retired, I worked at a place where "sit down jobs" were rare and highly coveted. And down through the years, management did everything they could to do away with as many sit down jobs as possible. They had an institutional belief that sitting tended to make people more comfortable and less productive. So after all that standing in my working life, you'd think I'd go for sitting at the loading bench. Hasn't worked for me yet. I've found that different presses work at different heights. Some have a longer ram, that's great for longer rifle cartridges. But usually a longer ram means long throw of the lever. In my case, I'm taller and a long throw on a press lever might mean that I have to dip down to move the lever to full bottom travel (or full ram height, your pick). One answer is to get one of those press risers that are made to raise up the whole press about nine inches. Puts your work more at eye level, raises the press action. How about you, sitting or standing?