Couple of observations from watching the Mudcats:
Enforcement is still very loose. Carolina had a couple pitchers always take 3-5 seconds longer to deliver and were never penalized, nor (from what I could tell) even warned. I'm not sure how to interpret this - the presence of the clock is sufficient to speed things up, there may or may not be more upside with strict enforcement, or they gamble on a call not knowing if an umpire is going to enforce the rule and make them adjust.
There appears to be no practice of hitters calling time during an at-bat, walking out of the box, adjusting gloves, taking practice swings, or any of the other stuff we see in MLB. They seem to be held to the pitch clock as much as the pitchers, and expected to be in the box awaiting the pitch.