I can't complain at all about either performance nor functionality with iOS 8. Everything is smooth and polished on the 5s - not so much on the 6, although the main cause is developers not updating their apps.
An issue with fragmentation was to be expected nonetheless, but the scaling was probably expected to perform way better than it does currently.
An issue with fragmentation was to be expected nonetheless, but the scaling was probably expected to perform way better than it does currently.