I had the flu last month (actually tested positive), and the Tamiflu seemed to get me back on my feet pretty quickly. At the same time, my wife took a prophylactic dose and she did not get the flu.

Similarly, 3 years ago, both of my sons and my wife tested positive, all saw improvements within 24 hours of taking it. I took a prophylactic dose that time and did not get the flu.

Anecdotal, I guess, but I would take it again in similar circumstances.