I have rented from Advantage a few times. The thing to keep in mind is they will try to upsell you EVERYTHING! As long as you know your auto coverage (what your home auto will cover while you are in a rental car), or your credit card coverage, (what that will cover in a rental car), and you can stand your ground you will be good.
I have a nice credit card that will cover rental car accidents if I used that credit card. When I told this to the employee she said "I don't think that is true, they are probably lying to you" I had gone over everything with the card company and looked at the fine print and I was covered so I simply said "I'm all set"
I went into the experience knowing that they would be pushy and was ready to stand my ground! I did and we had a nice clean car with no hassles in the garage on pick up or return!
I hope that helps!