Actually, for being an older plugin I was pretty happy with it for the most part.
One thing that others pointed out was that the Manage Competitions could not be found. It took some hunting but I did find it in the Posts menu.
Put in test environment. I could set the question, the answers, place it on page. It looked OK. User could respond. Cookies stopped user from responding again. I could close a competition, and reopen it again.
Only problem that stopped me from using this was the "Pick a Winner" function. When I clicked "Pick a Winner" I could not tell that anything had happened. I could not find a list of who had entered, or who was chosen, or if I was supposed to choose from a list.
I wouldn't mind trying this again if I could figure out who the winner was for a competition.