I prefer coffee futures, KC
I've traded coffee futures since the mid 90s, but these ETFs offer exposure to those who prefer something other than futures.
JO has better depth & liquidity, so I'd recommend it over JJOFF, but that's just an off-hand opinion - they track each other closely, so performance should be similar.
Also, as I posted on the other board - options may enable you to add some juice to the trade, and while options on both are super-thin, JO possibly offers tradable-depth, whereas JJOFF really doesn't.
Fwiw.