Highlights in my main bible (ESV) are taking forever to apply (> 20 seconds) in the 4.5 beta. The note file entry appears almost immediately, but the highlight in the text appears a lot later. This is probably related to the amount of highlighting already in the ESV--highlighting another resource takes only a few seconds. But 4.5 is taking much longer than 4.3 ever did (to the best of my remembrance).
EDIT: Well that last one I just did only took 10 seconds.