In the US you really need
Genie+ otherwise you'll be stuck in long lines all day. With Paris and especially during EMH, that's not necessary.
What also makes a difference between Paris and the US, is that in Paris the walkways are broader and the park is more spread out. So it might be just as busy, but d
On the other hand, it will be the busiest time of the year, as in July almost all schools in Europe will be off, and France has a national holiday on the 14th. Great for some special fireworks and Mickey & Minnie in French outfits.