When trying to compare gutter guards it's hard because you have certain assumptions. For example, you expect the guard to keep debris out AND let the water in, right? Well that's not a safe assumption to make because most gutter guards don't promise that at all. See this short video on Gutter Helmet shot in Seattle, WA to see why you should think twice.
If you choose harry Helmet over MasterShield, we have utterly failed in our efforts to inform you.