I am pondering ferry transportation (w/out car) from Italy (probably Naples) to Sicily since my flying options seem to be nonexistent using my FF miles. Is there any real difference between the lines.....And, what are the Pullman style seat like? I'm pretty sure an upgrade to a cabin would be worth it.
I've taken ferries, trains and planes from Napoli to Palermo, and I prefer flying. Check some fares, you may pay just a little more (or even less) than a cabin costs. Saves tons of time, too.
All the ferries are about the same in terms of cost and comfort, but some may be older ships (applies to any line).
I had the same FF miles problem getting to Sicily. I ended up using miles from PHL to FCO, then buying two separate Alitalia tickets from FCO to PMO (Palermo) on my arrival day. One was 3 hours after landing, and one was 9 hours after landing. That way, I was "protected" in case my arrival was late and I missed the first connection. I knew I'd only be using one ticket and throwing away the other one, and just figured the cost of the two tickets together as the total cost of my FCO to PMO flight. Since I was saving a fortune by using FF miles from the US to Rome, I was able to "accept" the cost of the double ticket, and it was much less stressful than worrying about missing the connection. I was also "protected" from having to buy a last minute ticket on the FCO to PMO route; for that day, the prices on that route were rising rapidly, and a last minute ticket was going to be over €300 (my total cost for the two advance tickets was about €150).
In the end, my arrival was on time, I got through immigration relatively quickly, my bags didn't take too long to arrive, check in and security for the second flight didn't take too long, and I had time to spare for breakfast before I had to board my next flight. But I was still very glad I had that second ticket, just in case.
Or, if you don't mind spending your first day in Rome, you can book a ticket for the next morning from Rome to Sicily (no double ticketing needed). Advance tickets on those routes are about €50, if you snag them early enough. Several carriers fly those routes, but one advantage of Alitalia is that you get one free checked bag. When I was traveling, Alitalia had 9 flights a day from FCO to PMO, and 11 flights a day from FCO to CTA (Catania). Note that while Palermo is a larger city, Catania has the larger and busier airport, with more options.
If you do want to book a domestic flight in Italy on Alitalia, don't use their US website, which marks up the prices substantially. Use their "international" site with the "English" option; this gives the same prices as the "Italy-Italian" site.
I have no experience with the ferries from Naples to Palermo. But unless you have a lot of time, flying is definitely the way to go.