How many User patches are there?
From what I have read the presets are not very good... Is it not sort of wasteful to dedicate those 3 buttons to bad patches?
There are 297 User patches, which are all copies of Preset patches, but you can change and over-write them.
Patches with the U:
prefixed on them in the GR-55 display are User patches, the Presets ones are prefixed by the 3 catagories, as you may have figured, the 3 preset catagory buttons are a waste of space.
Presets are generally not good on many MJFX devices, due to the presets are made to entice you to buy the unit, by showcasing extreme effects and features.
To showcase 297 patches of normal semi-dry clean guitar with a little reverb or delay may come across as boring.