Well, this episode crammed so much info in that I think it may have blown my entire perspective. I was hoping to get peoples opinion on whether tonight's ep blows my perspective or backs it up.
The way I see it is like this: if you draw to circles side by side and touching but not overlapping, I think that is a good way to look at it. When you leave one circle, being the island and the eloctromagnetic bubble that seems to encomposs the area surrounding the island, and going into the other circle, the rest of the world. When you cross the line where the two circles touch, the barrier, there are leaps of time... If one were to map out the barrier line they could place number indicating how much time would be jumped. If you hit the sweet spot, then you don't jump any time.

This is how I have looked at the whole tthing but tonights episode seems to indicate that the sweet spot is actually a spot at which you can cross the barrier w/o serious :"side effects." The chopper didn't hit the sweet spot, so it kicked off Daniels unsticking his consciousness from time.