Last time I checked, labara was only 2G data and their prices are low to reflect that. If you are a typical American mobile data user, that may seem too slow.
The only experience I have is with lefrenchmobile which supports 3G and 4G where it is available and we could usually get google maps working to guide us around. Some narrow streets in the old town sections didn't get reception, though, but all the buildings were brick or stone so not much signal gets through. Paper map for backup is a good idea. Tripadvisor, yelp and web browsing were good when the signal was good.
Lefrenchmobile mailed us our SIMs to the USA for a low fee and we were up and running as soon as we exited the plane.