Donmar exemplifies what a customer service-first company should be, from their president down to the installation crew and service technicians. They provide detailed technical info in "laymen" terms and their professional service fees are reasonable and commensurable with the quality products they installed. They don't push for products of which they are a manufacturer distributor; they take time to explain differences between various products by different manufacturers and let the customer make the decision. I also appreciate the fact that they don't play the game of quoting high and subsequently trying to beat the lowest quote from others. Overall, I had a good experience with Donmar in replacing both the gas furnace and the AC systems.