I am a day on this build and now I am a bit disappointed.
I did a clean install with all wipes. After your great AOSP 7.1 builds it feels... SLOW!:crying:
Everything works and battery is OK, but on Nougat is faster in all aspects.
Does file system of cache and date influence speed? (personally I feel that f2fs is slower than ext4 on Xperia SP, but maybe I am mistaken)
Feel free to ask me to test anything on this build!
For me it's very good and fast. but Nougat is better.
Try flash again or try factory reset. GOOD LUCK