The o-rings never give me any troubles, although I wish they were a big larger (to make the legs less likely to spin). I'm assuming you're referring to the bearings in the leg extension unlock thingy? I've shot both of mine in very dusty environments and had no issues. Here's a picture of one time I was out a couple years ago. This is after a quick wipe-down. 25-30 mph winds kicking up fine West Desert sand. Still works nice and smooth. I suppose I could see it getting clogged if you somehow got sand in there, but I've never had problems with mine in dusty environments.
To the OP, for a rifle that I am planning to use on a dedicated precision rifle, I wouldn't consider any other bipod. I love the Harris's, but the only real advantage they have is speed of deployment (which, admittedly, can be very useful in some situations). A quick search for Atlas bipods will reveal a similar opinion from many shooters here.