2 weeks in Spring in Southern Italy or Southern France?

That is an impossible question. I vote for Italy simply because Italy is one of my favorite countries. I have often said if I have to focus on one food group for the rest of my life, it would be Italian. Personally would think the potential for better weather would be southern Italy since southern France is still pretty far north.

I know it's an impossible question and I do love Italian food. Any specific places you recommend?

Spring in Tuscany is glorious. The concentration of historic sights is amazing; Etruscan, medieval, Roman, and Renaissance. Food and wine are world renowned. Scenery ranges from sea to mountains with lots of lush countryside in between. Tuscany would be my first choice.

Southern France might be a bit cooler than you're expecting, but I had no complaints about the May 2017 weather except for one total wash-out of a day. It's a particularly attractive area for folks who like relatively modern art, because so many of the small towns have art museums. There are walking opportunities, and I think the Provencal markets are better, on average, than what you'll generally find in Italy. I found the various cities and towns attractive, though I suppose that depends on the period(s) of architecture you prefer.

Southern France covers a wide swath of the country from the Spanish border to the Italian border. I wouldn't attempt to cover the entire length of that region in two weeks.

During your timeframe Sicily should be great, weather-wise, and it ticks all your boxes, though I can't point to any specific hiking opportunities I'm familiar with. I didn't do any significant shopping in Sicily and don't know what's available there. Two weeks is adequate if you'll have a car and are willing to go some culling of the list of possible destinations. If you plan to depend on public transportation, I'd suggest a bit longer than two weeks.

Two weeks wouldn't be too long in Puglia if you're fairly slow travelers. It's a very interesting area, with considerable architectural variety, but I think you'd really need a car [edited to add: if you're going to spend 2 weeks in the area]. You should include Matera in Basilicata.

Italy is blessed with a many other options; you could perhaps split your time between Puglia and the Amalfi Coast, though you'd lose a fair part of your vacation just getting to your first stop from your arrival airport and later getting to your departure airport. And it's not exactly a quick journey from the Amalfi Coast to Puglia, either.

In May 2017, we visited Nice and Provence. Provence is an absolute dream. We based ourselves in Saint-Remy, rented a car, and had a marvelous time.

In May 2018, we visited Tuscany. We stayed near Montepulciano. Rented a car again. Heaven.

You can't go wrong with either! The weather will be lovely in both. If I had to choose, I would probably suggest Tuscany for you. That's a hard choice, however. Honestly, I would try for both on separate years.

Italy is one of my favorite countries in Europe, however Southern France (Provence) is wonderful.

I see you haven't been to Florence. That city is a must see. Also, nearby Siena is great.

If you are talking about comparing Sicily with Provence, Provence would be my choice. However, were you talking about Naples, Sorrento, Pompeii, Capri and the Amalfi Coast, which you could easily spend several days.

Consider taking a river cruise in Provence. We started from Lyon and went into Burgundy for a bit then south, ending in Arles. That is a wonderful way to see that part of Provence, including Avignon, Viene and more. Don't miss St. Paul de Venice closer to Italian border. Nice is nice as is Monte Carlo.

I'm trying to come up with a comparison, apples/oranges - no, they aren't "special" enough. Maybe silk or satin. Or just chocolate or chocolate. Both are wonderful, both fit your preferences.

As I write, I am reminded that I loved Sicily over 2 weeks in April-May. The spring flowers were incredible in their colors and the sheer abundance, especially in the east. The Greek temples are wows, all of them. The mosaics as Villa Romana del Casale, the Palatine Chapel, Monreal, Ortigia, the myriad shades of blue and aqua of the sea everywhere. Okay, my vote is for double chocolate - SICILY.

Completely different and very similar.

Love both, and love both at that time.

Just because of my frequent trips to Monaco in winter I vote Southern France.

Who nose? Can't really help....

It is like tossing a coin - when the coin is in the air you suddenly know which way you want it to come up....