My wife and I did this last year through Reliance. We went this option (furnace and AC) only because our furnace crapped out unexpectedly and did not have the money in the bank after having bought the house a year prior to buy anything outright. I know we will pay more in the long run (that's a no brainer) but I make sure that they come out every spring and fall to run though everything for peace of mind and to get my moneys worth.
If you have the money in the bank, then better route is to buy outright; with rent/lease options the benefit is that if there are any issues they are taken care of quickly and without any stress on my part...plus it saved us from trying to find a loan for 7-10k
I completely get that, and in your situation it makes sense. Reliance , CTC , home depot ect. all do very well with a lease finance program. I didnt mean to sound like a wank, everybodys situation is different.
I was lucky when we did our last mortgage, I used the equity I had to back a line of credit so I could have access to thousands , no questions asked. When we were all done with mortgages I kept the LOC for a just in case rainy day.
Now you guys got me thinking, my furnace, mid efficiency is 20yrs old and the AC is probably 30, I should likely be buying a unit just because the blow up is probably coming.