looking at an amana 95% two-stage multi-speed gas furnace. looks to be a solid choice just looking for opinions about amana and this furnace. was told that the two stage gas valve burns at 50% or 100% if needed. i am replacing an lennox whisper heat and installing some much needed insulation in attic. Warranty looks good on heat exchanger and 1 year labor and 5 years on parts. was told that 95% seem to break more??any facts on that?? anything else i should be aware of..