Now back down at the base of the herd path, all we needed to do was re-cross the streams, do a bit of fast walking, some bushwhacking, and some biking, and we'd be done! We managed to do all of these more efficiently than on the way up (including the bushwhacking, where I chose a much better path through the brush than on the way in). We made it back to the bikes by 2pm, and were back at the trailhead at 2:20, for a total time under 8.5 hours. Not bad for Owls Head!
All in all, we found Owls Head to be perhaps less of a chore than we had expected, but that was in part due to the shortening effect of our biking and bushwhacking, and also owing to the great condition of the herd path leading up to the top. It's too bad we didn't get better views from the slide and from the top -- I was hoping to get unique views to Franconia Ridge and to nearby Bondcliff. Still, it's now done, and now I have only 11 more NH 4000-footers to go!
(update: well, not really, since it was pointed out to me that for official peak-bagging purposes, using a mountain bike along the Lincoln Woods trail is not permitted. I guess I'll be doing this one again!)
(Aug 17 -- further update: the re-climb has been completed. Click here to read about it)