Spent a few weeks in Paris last fall and used uber 2-4x a day every day.

Used it from the airport to the Opera area and there isn't much savings over a regular taxi, just a few euro. Around town the prices all seemed reasonable. I'm not sure if it is that much savings over a traditional cab but the convenience sure was worth it even if it was only close to even.

Never had to wait more than about 5-6 minutes for an Uber even in the middle of the night and cars were always clean and nice and drivers professional.

Going there next week and planning to just Uber all the time. I don't normally shy away from places after terrorist things but I'm bringing the family and avoiding crowded metro stations might be prudent for a bit.