Thanks for the information. I have pretty much decided not to even check other contractors. I have a few reasons, the main one being I am sold on the Trane units and always have been. I am sure that the other manufacturers make great equipment or else they wouldn't be in business.
I also realize I could possibly save money by shopping around - even with a different Trane contractor, but I did my homework on this contractor and have been impressed with all aspects of their business model. Yes, times are tough, and I don't have extra money to throw around, but I am going to go with my gut feelings on this.