I own two Kronos Subprime regulators, I am a UW photgrapher and Instructor, I use these regulators for both pleasure and fun and am very enthausiastic about them, I like the bubble deflector which sends the bubbles away from my face, fantastic.
The regulator breaths very comfertable and constant even in great depths (210 feet)
The regs are not over balanced but the difference is for the everage diver not noticable, the anti freeze cap on the Subprime makes that this so called over pressure effect is not working but there is no logic to that statement because the cap is transmitting the pressure the same as with the standard modell.
I choise for the Subrime because the HP chamber stays dry so I have less maintenance to do on he regs.
With both I scored abour 180 dives by now and didn'tsense any difference, I make +/- 300 dives per Year.
It is surely worth the invertment.