Matt Williams won the division and lost in the first round of the playoffs his first season as manager. Then he fell apart in the middle of the second one and got deservedly canned. Dusty hasn't even gotten to the midway point of season #2, so yhy don't we wait until Dusty does something the other guys haven't - get the team past the first round - before giving him an extension?
Lived near Cincy when Dusty was there, and though not a Reds fan (and in fact, the Reds were my chosen most-despised team, given their success as I was growing up), I listened to their flagship WLW and their sports talk shows regularly and came away with a very "meh" opinion at-best of him at the time.
These days, I'm more impressed. I feel comfortable based on what I've seen that he always has a plan and a back-up plan--never caught unprepared, and clearly has an absolute warehouse of a baseball database to reference in-between his ears, and instincts to go with it.
Extension? I'd wait, but there'd have to be an absolute collapse clearly attributable to things he coulda/shoulda done in order for me to not want him back. From where I sit, he just has naturally deserves a longer leash than a newbie manager from the git-go. So, I'd probably go ahead and start the negotiations behind closed doors, and just wait for that right moment in the season to announce it.