I just flashed 4.3 onto my Nexus 4, and I'm happy to say those annoying hiccups are virtually non-existent now! They really bothered me before. Chrome and Facebook were the apps I most noticed the stuttering in.
Are you sure this is not only due to the fact that you've flashed a new rom (you say flash so it's not OTA, I suppose) so the system is freshly installed?
I should try it on my Nexus S that has become sluggish as hell (and I've tried different custom roms)
