I'm no expert on pram vs. stroller, but at least for your time in Paris, be aware that it is probably far easier to get the stroller in and out of public transport (bus, metro) and up and down the many stairs you'll encounter. Many (if not all) cobble stone streets in Paris were paved over after the riots in 1968.

Strollers do seem to be more popular here.
Cheers,
Bev