The first set of articles, or at least the first article, make a good case for argingine doing nothing significant. Unfortunately in science, I can find a dozen articles on both sides of pretty much any argument. It's pretty frustrating. The second set of articles doesn't make the case for nitrates at all. In fact, one is solely about the arginine pathway since they used L-NAME (i.e. a NOS inhibitor that I use all the time). We'll just have to agree to diagree on this or it will go on forever

But if you want to send a sample my way, I'll gladly run it and give you my honest opinion.
And thank you for the solubility study. It does show a significant increase in solubility over monohydrate which is a big plus!