We are looking to replace an ancient boiler/chiller system in an 11 unit apartment complex we just purchased. We're considering using the types of units I mentioned above and I'm just looking for any pros or cons that anyone can offer. We're looking at a variety of brands and styles and it's hard to sort out for the first time.

Any input about things that have worked/not worked, energy efficiency, good/bad experiences would be appreciated.

Thanks in Advance,
Karla in Amarillo, TX

Ptacs are a good way to go for individual room conditioning that is probably the most economical replacement. I would suggest the heat pump with aux. heat strip package. Check out the Carrier or Amana.
These are easy to service or replace and are pretty quite. Mike