I had the Coinmaster Pro and was not very fond of it. The 5G was quite a step up from the CMP in the Prizm line as far as price (2x) but I don't know all the differences. I know the 5G has manual ground balance which is a big plus.
I like my Compadre...but...it doesn't have a sensitivity or ground balance adjustments. I would imagine the 5G is the superior unit in performance based on those two things alone plus it retailed for $550 compared to the Compadre at $160.
I think for the price of $200-250 you really couldn't go wrong. If you do go that route, look into a 4x6 coil for it too. It's a coin slayer in the tot lots and other trashy areas.
Good luck in whichever direction you go.