I think that is a excellent amount of time. A couple of years ago we spent a week seeing Rome, Venice and Florence. Two would have been perfect. Rome is the most intense. 2/3 days in Florence and 3/4 in Venice is plenty. We cruised Italy this year and stayed at the Grand Flora. It may be one of the best hotel experiences ever. The staff, the atmosphere and the Champayne breakfeast are all exceptional experiences.
While Rome is the only city in Italy I have been to so far, I can echo NumeroUnoPA regarding the Grand Flora. I spent 6 days there year before last and it was excellent. The location is good, the staff is wonderful, the accomodations were very nice. And as everyone says who has been there during good weather, the rooftop breakfast buffet is great!
Three years ago(this coming May)my wife and I made a 2-week trip to Italy with same purpose as you...cover a good amount of geography with the time alloted and in our case on a budget, using mostly points. The excellent train system made it possible to visit Milan, Venice, Florence, Naples, and Rome. We flew into Milan(United), stayed at the Marriott 4 nights(points)...made a day trip via train to Lake Como area(ferry to Bellagio,great)...trained to Venice but stayed in a Holiday Inn 2 nights(points) about 10 miles outside of city and shuttled in...trained to Bologna and stayed in Holiday Inn 3 nights(points), but daily commute to Florence was too much---would stay in or closer to Florence if had to pay next time, trained to Naples and stayed at Marriott/Renaissance(points) 2 nights--great historic fort there plus in walking distance is ferry terminal to all outer islands--Pompei, Sorrento, Isle of Capri for 1/2 day or day trips, trained to Rome and stayed at airport Marriott Courtyard 2 nights(points) hotel bused us to and from city...tried staying at Gran Flora, but never available for points,starting year in advance. We each had a 22-inch carry on bag and a back pack for ease of traveling on the train...worked out great...we plan to do it again in couple of years to see the Tuscany area and possibly back to the Lake Como area as can stay at one location and ferry to others daily...got to see a lot of Italy culture and great people observation on train...lots of local commuters...we did not use a rail pass and was not a problem...May was a good time to visit...not too crowded.
We went to Rome last September and stayed in a Courtyard Marriott near the airport on our way to Croatia. We had a great time staying in that hotel in the town of Fuimucchino. It a nice coastal town with many charming restaurants within walking distance of the hotel. Everyone who work at the hotel speaks English. They pick you up at the airport and it's about a 15 minute ride to the hotel.
Croatia is really the new area to visit these days. Not long ago, you never heard of any Americans really going there. We went there 5 years ago and flew into Milan, took a train to Triesta and rented a car and drove in from the North. But it's only a 1 hour flight into Split which is a fascinating city on the coast. It was built by the Venetians in the 12th century so the old city feels very much like Venice! It's a city full of young people with 4 universities. We proceeded to take ferries to 3 other island cities. There are over 1100 islands along the coast and many Europeans sail from one island to another. It's very beautiful and the water is more clear than I have ever seen in my life! It's much cheaper than Europe (which is ridiculous with the exchange rate now)but the food is not as good.
We ended up in the city of Dubrovnic. The return flight to Rome was only one hour as well.
I have included some pictures of:
BOAT LOOKS LIKE IT SITTING ON GLASS B/C THE WATER IS SO CLEAR IN CROATIA
LOOKING ACROSS AT HVAR (WHERE MARCO POLO IS FROM)
We did the same trip last summer in same amount of time. 4 days in Rome, 2 days Venice, 2 days Florence and the remaining driving North to explore Cinque Terre (a coastal must see), Parma (cheese), Modena (best vinegar/olive oil), Pisa, etc. We did the trip it that order. Take a train between cities, reserve in advance on Italy govt website to get first class seats for same as walk up coach (see link below), rent a car in Venice or Florence (be careful driving in Flornce, very crowded and they have cameras for issuing tickets back to you through car rental agency). For hotels, use the link below for Venere to see picures/rates/reviews. To reserve your hotels, this is Europes site for rooming reservations across brands and private hotels. http://www.trenitalia.com/en/index.html http://www.venere.com/ Use Frommers online for details, of what see http://www.frommers.com/ Your trip is very doable in 2 weeks, have fun, we will definitely go back!!
Take some time to stay at the JW in Capri. When people talk about Italy, you never seem to hear about the island of Capri too much. This is a hidden gem. Very relaxing with lots of shopping, hiking, great restaurants and small world charm. May take a bit to get there, but worth it once you are. The hotel staff was fantastic!