Having played both extensively, I decided to purchase a NIB Premium (my first NIB) last xmas and it has become one of my all-time favorite games. I definitely think the premium is the way to go on this especially considering that it's a keeper for me. The TREX mech is pretty awesome and the updates to the raptor pit make that feature a lot more fun on the premium vs. the pro. If anyone wants more detail, I'm happy to help...just PM me!