I was wondering if the following differences between an XR80 vs XB80 are worth the price differential (not sure what the difference is)

Four-Speed Blower Motor
Self-Diagnostic Microelectronic Controller
Heavy Steel Cabinet
Durable Adaptive Silicon Nitride Hot Surface Igniter
Upflow Models Have Hinged Blower Doors, Easy-Open Door Latches, and Spring-Loaded Filter Rack
Insulated Cabinet