The single most important thing with a new system installation is the quality of the install. Not brand, SEER, efficiency, etc. You need to know that your new system is being installed 100% correctly. Always ask for a complete start-up form so that you can ensure that it is being correctly put together.
Heat Pumps can be tricky for a lot of techs. Refrigerant will heat and cool your home. So as you guessed, there are many more working parts that are involved with this type of system. Make sure that your tech knows exactly what they are doing by asking "Have you repaired many heat pumps?"
Duct work has changed a bit over the years. Most is a flexible type and insulation factor is the important aspect. For many years R-4.2 was the standard, but that has now changed to R-6.0. The most insulated is R-8.0 and is the most expensive. Always make sure that it has a foil scrim outer vapor barrier.