I take your point about inspection, it is less visually elegant than a proper mirrored bowline. I find that the logic of this knot lies in the action and method of its tying for me, hence the video. The action of tying has an rhythm and tactile satisfaction to it, which I believe to be an important component to the ritual of tying on to the lead rope, although that might not be so clear from the video in which I have used a thicker rope (as well as lying the whole arrangement on a surface!).
On the point of the water bowline separating, I'll load a straight water bowline and show you what I mean, it's usually apparent after taking a proper "whipper" of a fall. I don't think that it presents a serious risk to the climber unless you haven't left enough tail, but the whole structure of the knot does tend to elongate or spread out as the knot is shock loaded.
The image of a water bowline on page22 in the document I think I have referred to:-
http://www.paci.com.au/downloads_public/knots/Bowlines_Analysis.pdf...illustrates the phenomenon.
- I suppose the water bowline wasn't originally adopted for the use of falling onto, more for knots that lie in the water, where movement can loosen a traditional bowline. This phenomenon is dramatically improved with the janus finish. One thing that I haven't included in my pictures is that I always tie a half fisherman's with the tail - very belt 'n braces, I know, but a habit I have carried over from years of climbing prior to adopting this knot.

I like the fact that the janus finish fattens the radius of the nipping loops too, which was one of the main reasons that I started using it, banking on that addition reducing the weakening factor of the knot.
Apart from the "bag of knitting, it has been called the "green" bowline, after its user!
I would also add that it lies reasonably flat which is an issue when climbing with double ropes on a rock type such as gritstone.
I have no means of testing its maximum strength, I would be curious to know if there is an appreciable difference between these knots and a conventional bowline.
cheers
D