It's at least my perception that while Miura will break while an arc is going on, it's usually not without a break in the immediate action. The last run of episodes for example, it ended just as they'll encounter the Sea God, but there was a clear break in the action.
You can't really tell when you read it volume by volume, but I think Miura has a definite feel for pacing, which is even more impressive given his irregular release schedule. Like most manga, it's more enjoyable reading it book by book, but in my opinion it isn't as painful as even some other series that are weekly or monthly.
But maybe I'm just used to it by now.