We had these guys install both a heating and cooling system in our house just before Christmas. Overall we are very happy with the product and the price we got the systems for. The gentlemen who did the initial estimate was upfront and helpful, and when I went into the office to discuss the specs and options, the salesman was very helpful.
The product (brivis heating and cooling) has been a godsend over the recent scorching temperatures, and we haven't had any problems which has been good (touch wood). The water use hasn't gone up much either, but this isn't a review of the brivis system!
However, it's not all chocolates. During the quoting and scoping experience the front office was poor at returning my calls and I always had to remain proactive. Not what I'd expect for the outlay of capital we were spending. And the finishing touches of the workmanship is a little to be desired. The cooling vents are good, although I think some aren't 'square' with the roof. While some of the heating vents are loose in there mounts and easily liftable by my little son. But I suppose the worst thing was the mess they left. Plastic bags in gutters (which I found thankfully before it rained), plastic off cuts and coke bottles in the driveways and ciggie butts in the garden bed. And don't get me started on the dust and plaster chips inside the house. Not sure if this is typical of tradies in general but I would have thought that a vacuum and a sweep would be part of the 'deal'.
Overall though, a great product at a good price with reasonable service. I would use them again, but I'd make sure the guys clean up!

Approximate cost: $6000+