CVT is an abbreviation of "Constantly Variable Transmission" so it feels like it only has one gear.
The issue I had with the one I rode with the CVT, was in comparison to an old gearbox where you selected the gear yourself. In a hunting situation, you select the gear and plod along at lower revs to keep the noise down. But the CVT at lower speeds never allowed this. It revs all the time, and you cannot control it. Noisy bugger of a thing.