Range RFD868 vs RFD900

Hi, regardless of location and local regulations which one of the RFD modems is actually better? There are 868Mhz and 900Mhz versions. And let’s talk about unlocked modems - those without the country suffix, so only RDF900x and RFD868x.

Which one of these will get you a better range and performance?

One would say, the lower the frequency the better the range but the lower frequency one also has fewer channels to choose from.