In getting a proposal for a re-do of my air conditioning system, one Trane dealer said he would/could not put in a Trane variable speed air handler as specified because of the nature of the existing ductwork that was done by the original HVAC subcontractor who knew it was to be variable speed. I told him part of the variable requirement is to minimize the sudden gush of air and noise when it comes on. He said I wouldn't notice the difference and that Trane had recently redesigned its variable AH and there were problems with it. I don't know what is wrong/inappropriate with the ductwork. Is he being truthful - is there some other Trane multiple speed unit that works like a variable speed but can be used with a variety of duct arrangements? Have there been problems with the Trane variable speed units? I have shown this system to 3 Trane dealers and none made this comment. I also had 2 Carrier dealers in and they said nothing about it either. What should I believe - I want to get the right/best thing. Thanks