You have obviously been deliberating about a flight from Santorini to Naples for a while. No-one can make your decision for you. Most of the complaints about Volotea appear to relate to add on fees, older planes and indifferent staff. If you are sure that you will follow all the rules with regard to luggage size, check in online, print boarding pass etc, you are happy with the overall price and flight times, then book it. A direct flight is a bonus in my book. You are holidaying in some beautiful locations, so if a short flight isn't great but gets you from a to b quickly, it isn't bad in the scheme of your lovely holiday.