My experience is yes/no. Depends on the dog. My SL female could care less.
My WL male will search relentlessly and excitedly for his kong, and for me. If my wife takes him out to do his business, sometimes I hide and he will search every inch of our decent size house until he finds me. If I hide the kong he'll go from room to room until he finds it. It's cool to be behind a door and hear him pumping his nose.
The best part is when he finds either it or me. The longer it takes, the bigger the reward seems to be. To watch the ears go flat and the tail elevation change as he rushes me is priceless!