Well, after having had the PK1s for about 3 months now, and the OK1s for 1 month, I've decided to make the PK1s my main phone.
The reasons for this are that first, the OK1s are not as comfortable in my ears. Indeed in extended use my ears begin to hurt. I've tried full foams, donut foams, the rubber rings. The donut foams were most comfortable, but my ears would still get sore after several hours, plus the second hole in the foams were always needing to be re-centered.
Secondly, I like the extra bass the PK1s have. The OK1 have tight, very well defined bass, but the PK1s just have more impact. With my main genre being rock with a little dub added, the extra bass is really nice.
I wish I had known about the fit issue affecting me personally, but there was no way without trying it of course. Oh well. Live and learn.
I'm going to keep the OK1s as backup buds in case something happens to the PK1s (God forbid.).