In the context of "guest host," Ken Jennings was a wise choice as the first post-Trebek emcee. A familiar Jeopardy! face to ease the transition.
In the context of "host audition," I thought he handled himself very well. Of course everyone will notice the ways in which he's different than Alex, but the new host can't be an Alex clone. Ken's greenness sometimes showed through, but that's to be expected. The episode still felt very much like an episode of Jeopardy!, which in my opinion, means he succeeded.
At first, I wondered whether the contestant coordinators strongly recommended to the contestants that they take the clues in order to help the new guy out. But then Tanay started jumping around the board, so apparently not. Jeopardy! can cover its edits more easily than most shows, so it's difficult to tell whether there were any glaring pauses or mistakes that had to be covered. (Two unrelated questions about Ireland in Double Jeopardy! felt unusual, but maybe that was just an oversight in stacking.)
