I installed the PB4 from Yosemite, was hoping it would install the latest one right away, but it started from the PB1 and had to update from that all the way to the 4. However, after using it a bit, and trying to use some of the new features while looking at YouTube videos "hands on," I noticed that some things looked or worked differently on my Mac compared from the videos. For example my Spotlight window is white like it was in Yosemite, isn't it supposed to be black? and it doesn't find anything new like weather, nor anything else, and I'm in the UK, which should be one of those countries where it works. Also, I can't find any way to open new tabs in Mail, like there's no way to open tabs. I wonder if there are other new functionalities I'm missing, but those are examples of reasons I decided to try the beta for, and they're just not there. I surely have the latest Public Beta though. Anyone has any idea why this could be happening? Thanks!