Pros: Never got the car that was booked, so nothing.
Cons: Didn't enjoy my trip being ruined due to not being able to get a rental even though one was reserved in advance. Spoke with Fox rental company who said "speak with Kayak, they tend to book no matter availability just to get the booking". When speaking with Kayak I was told that the problem was with Fox rental car. Miserable experience, would not wish it on my worst enemy.