transportation

I have been unable to find an airline called airitalia, so presume you are trying to compare the low-cost airline Easyjet with the major full-price Italian airline Alitalia. I am not sure which is actually the larger operator in terms of passengers, etc. I have flown Easyjet many times, and have never had a flight cancelled or seriously delayed. It does happen with all airlines, and probably an airline with more planes available locally would be able to find a replacement more quickly. Easyjet would probably transfer you to a train or bus, which is what they do if a flight is diverted because of fog, etc. Personally, I would fly with Easyjet if the prices are that different, but make sure I had allowed time for any delay, perhaps even travelling the previous day.

There would be no question in my mind - I would take EasyJet, even if the price were identical.

easyJet has very strict rules about baggage and advance check-in so it is essential to read the website carefully. Each choice you make, such as whether to check a bag, can increase the cost of the flight. But it is all spelled out so you can be pretty sure of what you are getting. easyJet is the second biggest all-Europe airline after RyanAir, based on number of customers. They have grown that large through efficiency and stringent cost-cutting. Alitalia is both a local and a transcontinental carrier so only its European destinations provide a fair comparison to the short-hop airlines. On that route you're not going to be in the air very long so you hardly need champagne service.

It is about 5 hours by fast train, some with no change, from Venezia Santa Lucia to Napoli Centrale and then an easy taxi to the airport for a very small fare if booked well in advance. The Freccia trains by Trenitalia are very reliable and very pleasant. The .Italo Treno red trains are fabulous and very posh; they even have free wifi and a movie car. Very fast, very pleasant, and super posh with lovely big leather seats - that's in second class. By the time you have spent an hour getting to Marco Polo and 2 hours before flight at the airport and an hour in the air the difference in time is very slight. The services are frequent. I note that if you organize tours and part of the transport is on .ItaloTreno they pay commissions.

I agree with Nigel. Take a train. If you've got to be there at a specific time, the train will do you well. Or go into Naples the day before you must be there.
We flew Gatwick-Pisa last year on EasyJet. They were flying quality airplanes with utilitarian, close seating. But when they say one carry on, they mean one piece (including purses, laptop cases, etc.)

Sandy, I agree with Nigel and the others. For travel from Venice to Naples, travel by high speed train, either with Trenitalia or Italo. It will be a far easier and more pleasant travel experience (and cheaper also, if you pre-purchase tickets and can get a Super Economy ticket). Cheers!