Thinking about putting a 19xl series system in a house with gas heat and want to zone it. Trane distributor wants to sell me EWC controls. Looked at their web site and this stuff looks like junk. What is the IZS stuff like? Will the EWC control my variable speed fan? I'm in commercial service and like Varitrac but that would be a bit much to install. In my work experience if you have Trane equipment use Trane controls. I hear a lot of good things about Carrier's zone control but I dont't care for their equipment.