I bought the '18 to avoid the '19. I'm not a fan of the new style, don't want a dial shifter, don't need an 8 speed tran, but I wouldn't mind it. I would never purchase a vehicle in the first year of it's production anyway...I don't like being free "quality control". All the new stuff is going to bring new issues, issues that they will not have the ability to fix right away. I'd give it a year or so or just buy the '18, you won't regret it one bit. I also chose not to get the Ram Box, it's nice, but it has it's draw backs too! There are other options for cargo space if you need it!
If you like the "latest and greatest" then wait for it. I'm hoping that the dial shifter for one goes away quickly....if it works, great, but I want to see folks actually use it and see if it holds up with strong off road use (I don't think it will). For on the highway...sure...no issue, but in the mud? No way.
Good luck with the decision!