Yglesias shares some wisdom:
I’ve never found speaking to important political figures either on or off the record to be incredibly valuable in terms of actual information. People are generally more willing to make jokes when it’s off the record, so it’s more entertaining to participate in those kind of briefings. On the other hand, it’s much easier to build an item around a direct quote so it’s more professionally valuable to be on the record. But it seems to me that the people who do the real value-adding reporting are mostly talking to lower-level people—nobody ever gets the real scoop from anyone remotely senior.