I used the beta for couple days, worked very good but battery life was horrible, omnistat showed constant high cpu usage. Usually indexing after new install does hit the Cpu, but this was for couple days, phone was running hot. Had to roll back to 9.2, however this is where my issues started. Restored back to 9.2, did not restore my backup and built from clean. However after getting back to 9.2, couldn't activate my iMessage, FaceTime or wifi calling. Doubt its related but incase anyone has the same issue, FaceTime and iMessage took half a day and finally activated, wifi calling took some weird work around.
Goto settings->cellular->voice & data->select 3G then back to LTE->then go back and turn off cellular data and back on, after that wifi calling finally activated.
Did you go to the Battery pane to see what app was using the CPU so much? I'm curious when I see these posts but people don't mention checking the battery pane.