I have nothing but good things to say about my experience with Uber while on vacation in Montreal.
Each time we used it the driver showed up quickly, and the costs seemed in-line with the fare estimates on the ap. A few times the final fee seemed lower. I'm not complaining.
We used it mainly when wanting to go back to the hotel after a night out eating and drinking in the Old Montreal area, and were too lazy and bloated to walk back. An $6-$8 Uber ride was so worth it in those instances.
Honestly, it beat driving our own car and dealing with parking hassles. Made our vacation time there a bit easier.