I've found the cheddaring pressing interesting as a process. As long as the curds are kept warm up to the final pressing, they'll knit well, even at the lighter weights I use. I use less weight because I like Cheddar types to be moister and more crumbly (big crumbs, that is!) than the heavier pressed varieties. The only difference is that my finished cheeses tend to bow a little after about 4 days of drying. In the past, I have compensated by leaving them in the press for a day longer so that the sides stay straight, but I now don't bother.
It's all a matter of taste, really, and my American husband and I have noted before that Cheddar types in the US tend to be pressed more heavily than in the UK.