As soon as I saw this thread I jumped into the beta version. Long story short, it was not a pleasant experience. Web pages sometimes had to be refreshed or they wouldn't load at all, display of web pages is dramatically slower, and Bitdefender seems to make the system hang on shut down for about 3-5 minutes. Sometimes the browser couldn't even connect to any webpage - even one that loaded fine a few seconds ago (I won't rule out Adguard causing a conflict with web scanning although it did not happen in 2016).
I have a very positive experience with Bitdefender 2016 but I can not recommend using this beta outside of a testing environment (2nd PC or VM). Really like the new UI though but the focus should have been on bug fixing then new UI.