We used Uber 2-3x per day during our recent visit to Paris. Always excellent service from very friendly drivers, at 1/2 the price of taxis. The only issue was occasional surge pricing (e.g. Thurs night in Paris, late Afternoon In Versailles.). Many short trips were only 5 euros and far quicker than metro (also cheaper for 4pp). Also ordered a van from Hyatt CDG this morning - nice Mercedes arrived within 5 min and cost was 22 euros. My only regret was not calling Uber when we arrived at Gare du Nord, where we waited 45m in a taxi line.