Stroller in Paris?

If he'll sit in a stroller and not try to be little Mr. Independent, I'd take it. You won't have to carry him, and he won't dart out away from you. It may take two of you to lift over curbs and down steps, but it would be worth it. I can't recommend a particular stroller as my kids won't ride in them anymore. Teenagers can be so obstinate.

Several years ago with children and grandchild went to Rome with stroller and it was worth it although the 3 year old was very used to being in stroller as they live in NYC. It can be a pain to carry it up and down metro steps but it was well worth it. If the child is not used to it, try to acclimate him to it before you go. You might have to pay extra fee with airline though, we went before they were charging for everything.

We found an umbrella stroller to be a blessing for toting a pre-schooler and providing a place to crash while we sat at cafes. You may hear that light strollers aren't up to cobblestones, but you don't encounter cobblestones many places. Most of Europe's large cities have modern sidewalks and paving. The advantage of a light stroller is that it's - light. Easy to collapse and carry up and down stairs.

In Paris consider using the bus system more then the metro, no stairs and there is a spot in middle of buses for strollers.
Do suggest a lightweight stroller, no avoiding stairs in Venice, all those arched bridges look like ramps, but they are often staired!

Sometimes it is not that the child's legs need a rest but that the child need his nap, so you can wheel the sleeping angel around while you continue to stroll or shop or visit a museum. The Paris buses are very stroller-friendly, by the way, as has been noted.

Umbrella strollers are what people use because they are compact, easy to fold and carry up steps. The large, heavy strollers used in the States (and driven around in the backs of cars) are not convenient for European cities. You could look for a MacLaren.

Thanks all for the suggestions. I have to agree with James about the non nap part!! :) Not particularly, when there is just so much to see. In my attempts at being optimistic, I'm hoping I can keep him in the stroller at least for some parts of the day and give ourselves a deserved break too!! :)