From an engineering standpoint, the Atlas is about as good as it gets. In my personal opinion, the Harris is not even in the same league. Do yourself a favor and see if you can find someone close to you that has an Atlas. Take it in the field and use it. Then you will be happy to spend the extra money to buy one.
I recently switched over to the Atlas bipods and they are far superior to the Harris in my opinion.....I have used Harris for many years and will continue to use their 25C for sitting position but for prone the atlas is much more solid....in fact I just ordered a second one so I don't have to swap it amongst my different guns.
You definitely get what you pay for....I love mine!