I tried the Surface Duo and while the form factor was nice, the software mostly sucked, and the camera was terrible. It was really good at separating apps that want to be full screen between the two screens. Been using a Samsung Fold4 since, and it has been much better usability, but the durability is poor, I got the extended warranty and have had it repaired for folding screen failures about yearly. When they pull the screen they also have replaced the battery so from that standpoint it has been kinda nice to get a refresh? What the Surface Duo and early Folds supported that is standout is a stylus, which makes taking notes fantastic on the large screen. The newer Folds from Samsung and Google have dropped this, so the screen would largely be a waste because rarely is having more than two apps open at once practical, and the square size means media isn't really better than turning a normal phone sideways. Between that and durability I'll probably get a Galaxy Ultra whenever I replace this Fold. If you need to multitask on a phone often it would be worth it, but that is pretty rare.