You should see how much a ten foot drag pulls. You can really feel it going up the hills. Allot of the times if I happen to spin out on a hill, it's because of the drag. I just unpin it, then climb right up, run a chain back down to the drag and haul the drag up once I'm on flat land. I've got a couple spots on our trail system where there's just a small little hill but steep and if you don't make it on your first shot, you end up spun out right down to the ground.
Just a tip for you snowbird...when you're pulling a drag, you don't have to have it full of snow all of the time. That will affect the amount of power you are using as well as being harder on fuel. I usually set the drag to where the second set of knives closest to the packer pan are rolling the snow. You'd be surprised how much fuel you save when you don't have a drag full of snow. Of course, if you hit a rough section of trail full of moguls, you drop the front of the drag a bit so the front knives are cutting more. Just looking at the picture you posted, that drag looks like it's built heavier at the front end similar to our 8 ft drag. I find our 10 ft drag hauls nicer than the 8 fter due to the extra weight up front on the smaller one.