I've only read the first dozen or so stories, but here's what I think so far:
The quality varies a bunch from author to author, which is probably to be expected. Most of the authors are pretty good, and I intend to keep reading. My biggest complaint is that "Starwolf," who writes the Tennyo stories, is not a good writer at all either in terms of concept or writing style; I find their stories unreadable. Skipping everything by him/her/it/them avoids most of the problem, but it does cause a bit of feeling like I haven't read the prequel (because, of course, I haven't) and also the backstory, which I think is pretty dumb, pops up and bugs me every now and then.
The writer for Phase/Ayla is probably my favorite.