I have a GT1. Cheap nd excellent little device but it does not have the functionality of the GT100 , hence the price and footprint.
It’s a great device for learning and experimenting and probably excellent for 99.999 percent of guitarists the last 0.001 percent being the edge. But it’s not as versatile or easy to use as the GT100. If you are a serious gigging muso then the 100 is probably easier to live with.
just my free unsolicited opinion.
