Zign Track could save you an enormous amount of time and could add alot of expression to your characters but you do need to spend some time initially getting used to how much movement to put into your acting. You will still need to animate the eyes and there is usually a good bit of tweaking involved but, when you have everything working well between your video performance and the character's rig, you are setup to turn out many minutes of lip synch and facial animation in a day.
I haven't had the time to do anything with Zign Track for ages but I was looking back at some of my early tests and found these:
I Wonder BabyPirate talkJust TalkingThose are very much rough tests. All of that jittering can be filtered out and adding eye motion would help enormously.