djanni:I assume you would not be concerned using the VT Pro?
I would happy to use a VT Pro (although I have never used one), but with any AI computer (using a transmitter) I ALWAYS have a backup SPG. The only two AI computers (with wireless transmitters) I have used are the Cochran Gemini and the Oceanic Atom and I have NEVER had any transmitter/link problems with these two, but I still think that a backup SPG is a good idea.
I have used an Oceanic Datamax Pro Plus and a Suunto Cobra on many dives (not at the same time). Both the Oceanic and the Suunto functioned flawlessly every time but I personally prefer the more intuitive (and larger screened) Oceanic.