I agree, he's "passable" as a creator. He's certainly become a better player in this regard.
That said, I disagree with your suggestion that his work during this summer was primarily involved in increasing his own playmaking abilities off the dribble as the primary creator.
To be brutally honest, I simply don't know what he specifically worked on during the summer. If you listen to him during interviews, you'll notice that he's pretty vague about it - saying that he worked on a lot of "fundamentals" with regards to his game. Pop suggested that the coaching staff worked hard to rectify a few "bad habits" that RJ likely picked up during his stint with Milwaukee. Knowing Pop, I'd wager that he was referring to bad habits on the defensive end of the floor.
Here's my point - thus far this season R.J.'s success hasn't been derived from some markedly improved newfound playmaking ability as the primary, initial driver. This is and always will be Parker and Ginobili's role on this team (with Hill being Pop's preferred heir apparent to Parker - though this is turning out to be a total disaster so far, but that's for another topic), and nothing has changed.
Even when R.J. drives to the basket, it's often as the secondary slasher once Parker or Gino have penetrated. That's where he's been successful at driving and finishing near the basket in the previous 5 games.
Today, he did in fact drive to the basket as the initial defender and finished successfully - once (in addition to driving and dishing out to Gary Neal once, hence why I agreed to call him a "passable" creator)- but this simply is not his game. This is what the Spurs wanted him to do last season far too often, and he floundered far too often because it did not jive with his style or skill set.
R.J. has not succeeded thus far being an initial playmaker. This is simply a fact. He's succeeded thus far shooting with phenomenal efficiency from 3 as the recipient of an inside-out game facilitated by either Ginobili/Parker drives or Duncan post-ups, and by driving hard to the rim as a secondary attacker.