If you want more happiness and joy in your life than smiling is definitely a good start, since other things mentioned above require not just change in your behavior but also your mindset. (blog.bufferapp.com)
Maybe it will have 1.5 points per everyday $ like the Freedom Unlimited on top of other things mentioned here? (flyertalk.com)
One other thing you mentioned in passing but i think is important is that you can use the citi premier as a vehicle to transfer all of your thank you points to hilton. (millionmilesecrets.com)