Snopes is good for some things, not so good for others. The people who run it are pretty far left.
(Try looking up their take on John Kerry's war stories for instance.)
As for their take on Annie Jacobson's story, the Snopes response has been around for a long time. Essentially, Snopes is simply taking the official denials and parroting them. The only real info you can get from Snopes on this story is that the Feds want the story to go away, and so do the people who run Snopes.
There were air marshals on the flight. I'll take their version of events, along with the flight attendants', over some woman (however nice she may be).
I wondered about their take on it. I read her book and I thought it was compelling.
That was my thought after reading the Snopes entry also.
Jacobsen's description of what they were actually doing on the flight, and her point that the air marshals couldn't actually see most of this due to where they were seated relative to the activity, is pretty compelling. Not to mention that every time something suspicious occurs we are always told by the FBI that it's nothing.