I extended the builder's gutters on my house with the DIY gutters, for about 1/3 the cost of what my grandfather paid to have the seamless gutters installed on the front of his house, for about the same length of gutters. But he did get larger gutters and downspouts, while I just wanted to match what was on the house already. I used the hidden hangers and the seams do not bother me. It has been 12+ years and no leaks. IMO it all depends on if you don't want the seams or if you don't want to install it and would rather pay the extra for pros. Also, the seamless is thicker and comes in a few different colors besides the standard brown, white and almond at the box stores.