Some brands are better than others - there is little difference between AG and IG except the stop in the header which can be removed. I have the SolarBears, had the SunHeater brand before and like the new ones better. The SH brand seemed to be a bit more brittle, thinner material, cheaper feeling. They damaged more easily when, for instance, a branch would fall on it during a storm, etc. The SB are heavier, more flexible, have a handle for adjustment of the header. JMHO, those are the only two brands I have tried.