Roberts Brothers Heating & AC

I contacted Roberts Brothers for a quote after another company (not named) gave me a 4-digit quote for the same work.
Roberts Brothers were able to give me a ballpark estimate over the phone, since I knew the work that needed to be done, then sent a repairman to view the situation and confirm. The main part that needed to be replaced (the heat exchanger) was under warranty, so most of the cost was covered, but I still had to pay for labor and some other fees. I was given an estimate of $550 and told that it would NOT exceed this. 
 I was obviously pleased with a quote so much lower than the other (unnamed) company, and had Roberts Brothers come out to do the work. The part, a heat exchanger, is not one that any repair company keeps in stock, but they were able to get it ordered and it arrived within a few days.
When the part arrived, they called me and set up a time to come out to do the work. The two guys who came out to do the work were professional and went to work quickly and efficiently, so the entire (major!) job was done in less than two hours. The actual bill that I got reflected this, as it came in at $520. I was impressed that the bill was nicely itemized, listing each part of the cost, so it was easy to see exactly what I paid for. This included the fees necessary to get the part as well.
Besides replacing the part, they also changed the oil filter and replaced the nozzle, doing what would be normal maintenance on my furnace.
Unlike some companies, they didn't expect me to pay before they left, but instead mailed an invoice to my house within a few days. I was able to pay in full over the phone with a credit card, which made paying simple.
All in all, a joy to work with, and I will definitely be using them in the future.