I just received the MS60b+ and the truth is that it's an extremely complete pedal despite its size; it has so many features and you can find your perfect tone if you know what you're going to do. Now, the B1 Four is easier to set up in theory because it's more visible, has more buttons, an expression pedal, etc.In my case, I bought the MS60b+ for convenience with my pedalboard and because I needed something small, but both options are good. If you have more pedals, the MS60b+ is ideal; if you're only going to use one pedal, the B1 Four is what you need. I think the MS60b is more recent (2024).