Just updated my iMac to version 3.0 of the Yosemite public beta and my iPhone 5 to iOS 8. No real issues to report in regards to version 3.0 of the public beta. It seems they have squashed a lot of the smaller bugs in the previous build so it runs pretty smooth now.
The biggest changes I think version 3.0 brought are tied into the iOS 8 & Yosemite integration: OS X and iOS compatible Airdrop and Continuity (Cellular phone calls on all Apple devices). Click the link below to read about it in more detail: