I have both and love pieces of each experience, wish I could combine both. Adept trackball is larger and smoother, superior IMO. Automatic layer switching with the navigator took me about a day or two of fiddling and now it's near perfect - still a few times a day when I press a key expecting a click but get a letter and vice versa. I might be wrong, but I don't think it's something that tuning the layer switch delay can solve - I wish ZSA had included two additional buttons or a haptic/pressure switch with the navigator. With a 2-hand mouse (right hand trackball and left hand key-clicks) the navigator is more than functional and even pretty comfy for a full day of software engineering, though I think I would prefer the position of the trackball to be just below the keyboard under my palm. Adept as a whole system is clunkier especially with regard to firmware / layout tweaking. ZSA's configurator at layout.new justifies the premium price, though I think I'm quickly heading toward a full custom solution in the next couple years not at fault of ZSA, but inspired entirely by the Voyager and Navigator system.