Yes you should tip the drivers
We are locals and use Uber (Uber XL) all the time we like to enjoy dinner at Epcot or over on I-Drive meeting up with friends and want to enjoy some adult beverages to go along with dinner, and when we travel... we have found the drivers to be really friendly and polite... the cars to be clean, we have been offer bottled water, and even asked if we needed to charge up our phones. We used Uber in NYC and loved it, some of the drivers where so funny, and gave a lot of history and low down on what to do, where to go, and where not to go.