I have & adore both. Some may think that it is not worth it, but I personally love the idea of having a little Louis on me everyday. I don't feel comfortable enough (yet) to carry my bags to work, so glancing at the bracelets while I'm typing away gives me such happiness!
With that being said, here are a few pictures that I hope will help you.
The charm on the Luck It is darling and I looove it.
Keep It feels more casual - I have been wearing it everyday since May. It was an anniversary gift and my boyfriend has the same bracelet in Graphite.
In the end, I am no help as to which one to get... I say get both!