First, I will tell you that ALL gutter protection systems have some inherent faults. None is the 100 % cure all for every leaf or pine needle or flowering bud scenario.
My personal favorite for multiple conditions are the cheap plastic 3 foot sections with small diamond shape punch out patterns with a laminated filter, similar to a window screen as sold by Home Depot or Menards and probably Lowes too.
The expensive systems all allow small mulch like compound to travel into the gutter trough and decompose into a caked on mud like substance.
The absolute best defence against clogging is to have a substantial pitch to your gutters, to have a sufficient number of down spout locations and to use the oversized 3" x 4" downspouts instead of the 2" x 3" downspouts to prevent clogging at the drain opening.
P.S. A good site for gutter guard comparisons is located at
with many articles written by Tim Carter and he has about 5-7 articles comparing various gutter guard products, and draws the same conclusion as I do.
Last edited by Ed the Roofer; 07-30-2007 at 10:10 AM.