Considering the Trane XL20i. Have heard they redesigned the air handler last year to put the evaporator coil on top (at the supply end) and the blower on the bottom (at the return end). Does this new concept of "pushing the air across the coil up to the supply" work better or worse than the old concept (that everyone else still uses?) of "pulling the air across the coil and up to the supply". The Lennox dealer said Trane did a bad, bad thing and it causes air "leaks" in the a/h cabinet.

Anybody run into this as a problem? Also not sure if it applies to the XL20i with a TAM8 air handler, or if the redesign was only the TAM7 and the GAM(x) series.