Bests & Worsts Reviews from Amazon

I was nervous about buying a thermostat, but I checked their compatibility test and it said my system was completely compatible. Then, after installing, it told me I needed to hire a "nest pro" to run another wire from my HVAC to my thermostat. I feel like their "compatibility test" outright lied, telling me my system was compatible when it wasn't. Please do not buy if you don't have a C (common) wire or don't want to have to pay someone to install one.