@PREMIERJAX:
Yes, these are bunch of guys and some questions do tend to set them off at times. Sometimes you have to just ignore them and look for the more helpful responses. Reacting to them only feeds the trolls. Let their comments speak for themselves. If they wish to appear like 12 year old children, well, that's their choice.
I didn't know the answer to your question either, and some of the answers here were actually useful. I hadn't considered the taper of the pole to be an issue. That makes sense. As for round poles versus square- well, round poles were the standard for many decades, so I don't buy that argument. But times change. Now that square poles are available, yes, that would simplify mounting to the poles and may be worth the extra money just to have that ease of use. But that's a decision you'd have to make.
Personally, I think if I was going to be spending that much money, a little more for the square poles might be worth it to avoid the annoyance later.