Exactly! Round pen work or lunging, or any other form of exercise, it's all about what kind of outcome you want. Do you want to 'just get on and ride', or do you want to be able to execute a particular manuever in a particular way, in *that* precise location? Both can be fun, but you have to know what you want out of your horse *before* you ask him.
Tell you what, I was seriously wishing for a smaller location while teaching Beren to lunge. It took a while before he didn't lug to the outside, or worse, cut off half the circle and make a mad dash for freedom. They never show that stuff on TV...
BTW, I'm envious of your beautiful flat grassy location... nothing but hills and limestone around here.
Yup... that's the gripe. ;~D
Bay tends to lean on the lungeline for balance, which tends to make him less balanced and his ass goes out from under him at the canter, particularly if the grass is slippery. Switching to long reins, instead of a single lunge line on the halter, is good for correcting that, because it gives you an outside rein.