Place / Show Wagering I think there are very very few instances where a Place bet is a good bet.
Your payout is directly correlated to the other finisher. Since favorites win the most, 2nd favs win the 2nd most, and so on...you are always putting yourself most likely live to the worst payout on your opinion, 2nd most likely to the 2nd worse, and so on. Now, let's say you hate the favorite though?...well in that case you are much more likely to have found an overlay in the Win Pool than you are simply having the previously mentioned Place likelihoods upgraded one spot.
Logically, place bets just don't make sense to ever make outside a few exceptions where you're identifying weaknesses in the market.