I've been to both, although only Rome in Winter, and I would probably choose Stockholm out of the two. I found Rome dirty and loved Stockholm. Mind you, I was in Stockholm in Summer and it is a city with lots of outdoor stuff to do. As one of the PP said, why not do both? I would probably say that there is more to do for kids in Rome, although like the others have said I would stray away from Rome a bit as well. I'm another that LOVED Florence and I actually visited Venice in Jan and didn't notice any smell at all.

It all sounds so exciting!!! And such a great plan for Christmas each year!! You're prob more likely to get snow in Stockholm and the Scandinavians do Christmas beautifully!! Oh, you've got my itchy feet going!!