I like it so far, the predictions are pretty good and my Swype beta always lagged when i opened my messaging app to use it, and although it was maybe like 2-3 seconds, it always bugged me, flow pops up right away and is ready for use. I am going to keep it unless it really starts to irritate me, but hey, its a beta so let it be tested then wait for updates.
EDIT: To add as well, in the apps that do not use the Flow option, which for me i like because half the time in the play store some apps are named weird names and aren't recognized in the English Language, like UCCW, GasBuddy, etc, so i would just type them. Same with the browser, too many errors to Swipe.
They do need to add in a predictive text when it is switched off of the flow option though, because right now, and i understand it is in beta, there is no way to predict words you just have to get them right.