I've used Hargrave in the past for some parts. I like DIY and they were super helpful getting the right parts - which were in stock and getting them to me after hours so my family didn't have to be cold.
When my furnace was acting up, I called them and they arranged to meet me ASAP... That meant coming to my house super early in the morning to fit us in....
The technician explained to me what the problem was (cracked heat exchanger) and the symptoms that brought him to this conclusion. Hargrave quoted me some options and because of their excellent service, I didn't want to shop around.
Being an Engineer and a cheapo, I typically won't buy the most expensive option. But I was curious asked what the differences and benefits are. They obviously know their product and I can appreciate the premium product.
The quality of the installation is excellent. I like how the technicians were very detailed and clean. They tucked in the piping so I had to look for it. Furnace was taped up to prevent leaks.
If you choose Hargrave, I think you will be very happy.