Dude, that was seriously harsh---sending your own kid back knowing your younger self is going to kill him.
So...after the experiment, Daniel was time-jumping like Desmond. Going back to island saved him...and eventually killed him. How sad.
I wish we'd spent more time with Daniel and less with paranoia-Joe and the Dharma boys. Overall, I'd give it an Above-Average.
And after watching the preview, it seems Jack is out to do another bone-headed maneuver in order to "save" everyone.