Has anyone here invested in energy efficient appliances and found the savings to be meaningful?

I'm planning some home improvements in the summer and my contractor told me about benefits for energy efficient utilities. If I get an energy efficient furnace will it pay off in the foreseeable future (let's say 3-5 years)? I was looking at two programs:

Home Energy Loan Program along with Enbridge's new program, suggested by my contractor.

For those who have installed energy efficient furnaces, what has been the monthly price difference (in Toronto - Enbridge). If I purchase the furnace with this loan, could the energy savings + Enbridge's program counteract the interest?

Thanks for the help