The system is quite straightforward to run.  Each TV has a simple hand-held remote.  Whole house music is turned on and off at keypads for each room.  Thermostats are on each floor.  Music can be changed with the touchpanel, iPad or iPhone.  A demonstration can show you how easy it can be.

There are several layers to a system like this, most of them are permanent and require no maintenance.

Physical infrastructure like wires, acoustic treatments, racks, patch panels, etc, generally require no maintenance over their life.

The speakers and amplifiers along with power distribution, fans and switching generally have very long lifetimes - 20-30 years is common.  Lighting control systems also have a similarly long life.

The control layer - the control processor, switchers, are very straightforward, extremely reliable and fairly common.  This is the only area where specific expertise for maintenance is needed.  There is a video switcher distributing video to 4 rooms (theater has direct video sources), a switcher sending audio to 8 rooms and a control processor.

The area of the highest maintenance + most complexity is the sources - Tivo, DirecTV, Gaming Consoles, AppleTV, etc.  This house experiences all the same issues as any house when DirecTV has a service failure or Comcast screws up a connection 1/2 mile away.   All of the sources now distribute regular firmware updates, rely on services from their vendors and are the source of 90% of all maintenance issues.

In the end, more maintenance than a stove or fridge, much less than a boat or fancy sports car.