UberX is cheaper and has fewer cars.
The uberX cars are typically cheaper because they are smaller and have a shorter range, which means that more drivers can serve the same radius of people (think an entrepreneur who might only own or be able to drive one car). They also offer cheaper rates per minute or even by mile. It’s usually slower than regular Uber, so if you’re in a hurry, stick with your run-of-the-mill ride. Waiting an extra 15 minutes to save 3 bucks may not be worth the time if for some reason its a big deal that you get there when you want.