Is that what you base stand alone Navigation units are "Rubbish & Clunky" ?The last one was a Tom Tom 450. Pile of utter shite. Hideous mount that squats on your handlebar, too.
Ive been using stand alone Navigation devices on my motorcycles for over 30 years. I've seen them come on. I agree, some units are rubbish. However, There are some very good units available now, Currently Using a Garmin XT, Great unit. You really should have a look at the XT (2) and the new Navigator. They are not slow & clunky. Its a touchy subject, Like oil and tyres. Many are branded.