The Atomics and MK25T are balanced pistons, but they have little in common with the older Sherwood piston regs. The old sherwoods are "flow by" pistons very much in the MK2 design. They are "balanced" by using a floating orifice on spring washers that compensate for decreasing downstream pressure on the HP seat. It's not really air balancing, it's just supply air pressure balanced against spring pressure. It's a proven design, though. It has limitations in flow rates, but those are probably fairly inconsequential for recreational diving.
The atomics and MK25 are "flow through" pistons that are also not exactly air balanced but the design is such that the downstream supply pressure has minimal effect on the IP. The MK25 piston (and I bet the Atomics) are even designed to compensate for the slight effect on IP, and can have IP remain within a couple of PSI across the entire supply range. They also can produce very high flow rates, much more than either the tank valve can supply or the 2nd stage can handle.
If you go from a Dacor reg to an Atomic or MK25 you're probably going to notice a big difference, but that has nothing to do with the use of titanium or stainless steel.
You might also just try any sealed diaphragm, like the MK17. Since the ambient chamber is sealed, and you can rinse the outside easily, corrosion is not a problem.
