Put another way, your inspector probably won't allow a three-handle mixing valve on a remodel. Codes require anti-scald which can be done with a pressure balanced valve or a thermostaticly controlled valve. While more expensive, I prefer the thermostatically controlled ones - set it to your preference once, and only touch the volume control. Another thing, a pressure balanced valve typically only has on/off/temperature - it has no volume control if that is a factor for you. Normally, that isn't a big deal as you typically fill a tub or shower at max volume, but it can come in handy at times.