I fitted a Vector to my TTR, also used the dashboard so i get the 4 warning lights.
It's realy easy to use, and read at a basic level, if you want to use the various computers you will need the extra handlebar switch.
Trail Tech in the UK were really helpfull, and very quick with getting the unit out.
The new units have a connection to the bikes power so you don't run the units lights from the internal battery, the older units just run from the internal battery I understand.
The only 'issue' is the monkeys at the MOT Testing Centre who find it impossible to record the mileage on the forms - they seam to struggle to press the MODE button to see the ODO, other than that I'd have no issues with swapping.
I did keep the old unit (that doesn't work!) from the bike to varify mileage if I need to, can't see I'll ever need it though.