Whatever "generation" you want to stick them in, the provari and the darwin are the only units in it right now. Active power management was the last step needed for a truly modern PV. At most, the only thing someone can do to innovate now is combine active power management with juice feeding. Well, that, and lowering the price quite a bit.
Interestingly, the original, standard 510 battery uses active power management. It wasn't adjustable, but it uses a timer and a FET to get ~3.2V out of a 3.7V battery. The Ego works the same way. From an EE standpoint, the only difference between an ego and a state-of-the-art PV is a 2nd LiPo cell and about $10 worth of electronics.
Interestingly, the original, standard 510 battery uses active power management. It wasn't adjustable, but it uses a timer and a FET to get ~3.2V out of a 3.7V battery. The Ego works the same way. From an EE standpoint, the only difference between an ego and a state-of-the-art PV is a 2nd LiPo cell and about $10 worth of electronics.