I have the OK3s, and love their ear bud sound (somewhat better than the PK3s). But as I have said, the canalphone version sounds veiled to me (and Souperman, who also reviewed them in the OK3 thread) mainly because I can't get a good seal as the earbud blocks decent insertion. Unless the longer sound tube changes that situation, I won't be using the canalphone option with them. Plus, I also have the Sleeks, which are far superior to the OK3s (and should be), for in-ear listening.
Of course, the OK1s may be a different story due to their price, and could rival the Sleeks SQ-wise, though I doubt that will be the case when the former is used as a canalphone. But you never know.