I'm looking at the MAX and the MAX Plus, what is the difference, and which one should I purchase?

The only difference between the MAX and the MAX PLUS is that the PLUS comes with a pry shield as the Max does not. (The same is true of the MINI and MINI PLUS). The Pry Shield is designed to help prevent prying attacks and comes with tamper-resistant screws. Did this answer your questions? Thank you for your feedback