Home warranties are great if you use them and not worth a darn if you don't. I have done work in the past for some of the main companies offering home warranties.
When these companies have to pay for a repair they are naturally trying to have it done as cheap as possible. They try to find the cheapest contractor and parts. Mostimes you get what you pay for.
I myself would never, ever, ever by one of these. Of course anything that breaks in my house I can fix or replace myself.
When a home warranty company sends a contractor to your house to fix something just remember you are not paying them and you are not the customer. The warranty company is and they dictate how things are taken care of.
I would rather have a contractor of my choice to the work I authorize in the manner that I want. But hey...it is your call