I have a 6 year old house we bought new. Came with a 13 seer Goodman Heat Pump 2.5ton and a ARUF model single speed air handler. House is 1680 sq. feet. Have had horrible heating and cooling. Replaced leaky evap coil in 2009. Coil is leaking again. Want to replace the entire system. I have had several companies do estimates. Most reputable ones measured rooms with lasers, did manual J and wrightsoft computer calculations. Several companies said we need a 3 ton. Others a 2.5 ton. The difference is that the one said we need the 2.5 figured the average summer temp at 90 degrees which in Durham-Oxford, NC is too low. The others figured 95 degrees. This past summer we had several 100 degree days. We have 9 foot ceilings and vaulted in den and bedroom. Two returns. One 20x25 and one 14x20. The air handler is under the house. I am leaning toward the 3 ton. I do not have a trunk line. It is all flex duct. I am having air flow issues. One end of house is cool and other hot. Cheap dampers are installed. Do I need a trunk line? Have been heavily considering the Trane XR15 3ton with the variable speed TAM7 air handler called a HYPERION. American Standard and Trane are the exact same unit. Have gotten estimates on both. I also looked at the Heil 17 seer quiet comfort two state DXT with top of the line variable speed air handler. I have spent $2000 in six years keeping the goodman serviced, repaired and going. I quit. Air handler is not under warranty. All alum. coil and labor is another $. No way. So lots of contractors are bad mouthing Trane right now saying they are troublesome. yet my dad has Trane and no issues. I had Trane in 2000-2004 before moving and no issues. Why are so many people bad mouthing Trane? Cost is not an issue. I want this right. Estimate for a round trunk line and Trane XR15 2.5 ton 16 seer and TAM7 were $. installed by a Trane Comfort Specialist. I hope I can get some feedback. I am tired of being taken by people in the industry who keep steering me the wrong way. Got estimates on Trane, Am. Standard, Heil, Ruud Rheem and Carrier. All are not that different. Most are $. I just want the most reliable equipment by a good contractor that I can get. Any help appreciated.