I used to use jump breaks when I was blogging a few years back on Wordpress.
But, in my current blog, I prefer to display the full content. Same with the rss feed - no truncating.
The reasoning is that now people don't have patience now to click on something to get more info. They just see whatever is available on the 1st click and then move on.
They would rather click on another topic link, than click "read more".