According to a 2014 comparison by FurnaceCompare.com, Trane brand heat pumps are significantly superior to the Carrier line. The review lists three Trane models in it's top 10 for the year: the XB14, XL20i and XR15.
No Carrier models made it into this list, which reviewed 250 series of heat pumps sold under 45 different brand names. The Trane XB14 actually topped the list with a rating of 4.2 out of 5. This model features a maximum seasonal energy efficiency rating of 15.5 and a maximum heating seasonal performance factor of 8.5. The unit generates approximately 76 decibels of noise while operating and retails around $6,200.