As far as repairs, the loop is just a plumbing job (you can handle it yourself), pumps and pipes and a little wiring. The unit itself is just like an air-to-air heat pump but in one compact unit that uses the ground water in the loop instead of a fan and air. Should not be any problem for a qualified HVAC repair person. This is not just me talking, my brother is an HVAC contractor in Florida that does all types of heating/cooling units. He says he can handle any geothermal unit made (although he deals for Water Furnace also) Don't be scared off by a purported lack of repair folks, that just isn't true.
The equipment is expensive, but it's clean and quiet. If you can afford it I think you would be very happy in the long term. We sure miss it (bought an existing house with oil-fired hot water heat).
Bill in Ohio