[jeff5may]

Austin,

The main question is: What do you like and how much control do you want to have? This will help you determine what's best for your house. You and your family will be living in it, so you might as well think about it for a while. Each type of system has its own merits and disadvantages, so after some research is done, you will gravitate towards one or the other pretty quickly.

I assume you have a good idea of central ducted HVAC systems and their virtues. Unless you are planning to install a home automation system and zone controls, these pretty much deliver air to everywhere you might want it, how and when you want it. Performance comes from having a highly competent (ace) contractor do the inital design/install. The energy savings comes from:

1. a well-insulated and balanced duct system
2. zone control, either manual(at each vent) or automatic(expensive)
3. a high efficiency, multi-speed outdoor unit (expensive-r)

In contrast, a multi-mini-split unit like you are considering usually has an infinitely variable (inverter) compressor built in that uses only the amount of energy your zones command. Some have programmable, hard-wired controls as an option, but most are simply adjusted at each zone as needed. The indoor units have a decent amount of throw, so they do a much better job than a typical window shaker unit, and can be strategically placed to condition adjacent zones when doors or vents are opened. Performance comes from doing your homework up front, both in choosing a unit that will fulfill your needs and carefully considering indoor units' placement.

It sounds as if you are already leaning towards a central, ducted system. Make sure and pick a unit that will satisfy your demands (including free hot water), there are literally thousands to choose from! Above all, ensure the ductwork is well insulated and sealed before enclosure. These two steps wil pay for themselves over and over again.