I have booked through them tree times and never had a problem. I have my own rep and he has taken good care of us.
On one cruise Princess told us it was to late to get two rooms across from each other (inside & balcony) and some how VTG hooked us up.
My last cruise on Royal Caribbean we decided to use a friend who is now a "cruise specialist". Just for kicks I checked VTG, talked to my rep and without telling him about my friend he got me a better price and more on board credit.
Shop around would be my advice but give VTG a shot.