I think GD's accessment of the malibus and mb's are right on.
I am glad malibu is going with bigger diameter hose and higher volume pumps and I love how simple it is to piggy back the ballast with just a few connectors and hose lengths.
The purevert system(s) are really great if you do not want any extra weight. I do not like how they havent figured a way to piggy back em yet, that if you want extra sacks you either have to 1) fill them with portable pumps...booo or 2) add pumps and switches, cut holes in the hull, etc... no good either way.
The best system would be a purevert with piggybacked sacks that when stopped or idleing, the ballast would drain and when boat speed exceeds 10 mph or whatever, the ballast would fill. that would save gas, get the boat up on plane, and allow for even more weight.
for surfing, you would just open the gates to fill whatever side or tanks you want, then close the valves so it will not drain while surfing.
some boat company... go. your boat will be my next.