This anime is essentially a spinoff featuring the Gold Saints of the original storyline. It's an excellent idea. The Gold saints were always badass characters, and I think it was always a secret wish to have them as heroes instead of the 5 bronze saints we got instead. So this story is essentially just an excuse to have the Gold Saints fight their own saga, and also give honor to the series in general.
I believe that the story was on par with something like the Asgard or Poseidon arc. In other words, a fairly cookie-cutter arc with good guys and villains, and a storyline just there for fights to happen. The story does retcon some things, and especially obvious is the fact that the Gold Saints seem a little cheapened compared to their glory days in Sanctuary. But then again, this was done already in the Hades arc. In addition, the personality of the saints is noticeably less "imposing" than they were in the sanctuary arc.
However, despite all this, the series is still pure enjoyment for the Saint Seiya fan. The original cast of actors is also there (except the ones in the afterlife, RIP), and although some sound very old, in this case its very enjoyable for obvious reasons (pure fanservice). We also have some saints which were just overlooked in previous sagas as evil (Cancer & Pisces) being redeemed here.
The art is on par with what had been seen in Hades arc, so acceptable modern style. The music is not on par with the beautiful original, but again also acceptable.
All in all, I would call this anime pure fanservice to the Saint Seiya fans of the Gold Saints. To be watched without serious thoughts about the impact on the canon storyline, and as a pure spinoff of the main series. Still, I found it enjoyable and give it a solid 7/10. I think this is on par with Asgard, Poseidon, and Hades arc. Nothing will ever equal the Sanctuary arc, and to many fans (including me), everything else is a spinoff. So watch this just as another spinoff arc.
