I have had seamless gutters with the debris guards on my house here in VT for about 5 years now. Willey's Seamless Gutters (
http://www.willeysgutters.com/) did the work. They are a VT company but, I got the impression that they would travel most of VT and NH for installations. (I live in the Upper Valley on the NH border) I have been extremely happy with the gutters. We have a standing seam roof and the snow slides right over the gutters and guards without any trouble. We have never had issues with snow melt freezing in the gutters. It is so nice never having to clean the gutters. They certainly are not the cheapest option for gutters, I think it was about $2,500 for about 70 feet of gutters, but being maintenance free is a huge plus!