2 stage is really nice and a DC blower fan is apparently more reliable and quieter spin up my plumber said. He also said your furnace will last a lot longer and in particular the heat exchanger if you regularly get the gas pressure valve adjusted. He said a common reason for heat exchanger cracking was the furnace running too hot because the valve would let too much gas out for too long and the exchanger was having to deal with more heat than design. I trust him because he's a good friend and that does make sense.
Apparently the mid efficiency furnaces are the best and most reliable but king trudeau won't let you buy them or buy heat exchangers for them.
Z32 TT
1996 Integra - winter beater with studs - RIP (deer)
2002 WRX - to be sold
2010 sti - winter