Nice tones. I have a GT-5 and a GT-3. Both are extremely functional, but also somewhat complex, and I often experience the same feeling you did with the HD500. I have thought about the ME-80 myself. I like the simpler knob layout as opposed to the push-button/menu layout on the GT units.
Don't get me wrong though...A working musician who is working with a specific set list, and a sound guy to adjust levels as needed, could easily set up the more complex units to correspond with the set list. For small gigs without a sound man, and tunes called on-the-fly, the ME units with the knob interface would seem to be more practical.
I guess it all comes down to "the right tool for the job".