the pole will be stronger as its screwed on to your roof gutter using wingnut clips. The other is a lenght figure of eight tube open at the top and bottom that just hitches on, i dont think it would be too secure in a high wind but it would be great for quick release.
figure of eight
http://shop.justkampers.com/product_info.php/cPath/5_4065_4401/products_id/10324
the clips to gutter for the pole variety
http://shop.justkampers.com/product_info.php/cPath/5_4065_4401/products_id/10316