Under iOS 8 (and 8.1 beta) the performance of creating an NSAttributedString is much worse than 7 (2-3x). This is especially noticeable if you\'re using multiple instances o
At WWDC this year (2014) I brought this behavior up with the TextKit team. Specifically, I was elaborating on how some of us need support for asynchronous HTML parsing. They were surprised that there is no public API for attributed string creation asynchronously.
Given that the core of some of our apps deal with rendering large amounts of HTML text, the system provided rendering is less than ideal even on iOS 7. So, I was told to file a bug; the more bugs that are filed about this issue the higher the likelihood of Apple addressing it.
My suggestion is to use DTCoreText, they provide exactly what we all need regarding this issue. The only other solution is to wait.