First hack I ever 'completed' was ShinyGoldX Beta 5. I had a terribly limited internet connection at the time, and so it was a pretty massive deal for me to actually get it (yes, I'm aware that IPS patches are mere kb-sized files). I'd figured "You know what, I've played original Gold a lot, so why not go for the challenge version?
Aaaaaaaaaaaaaaand I was so so so wrong. It was so damn difficult. But eventually I managed to make it to the end of the release, which had most of Kanto done, if I recall.
Unfortunately, though, it never truly completed.
It's a shame that Zel never completed it. It was by far the best hack back then, it was one of the first to really get near completion. He used the tools he had back then to make something... extraordinary good. Some people may claim that Liquid Crystal was better, but LC was completed years later, when the knowledge/tools were already drastically improved. Giradialkia, do you think Shiny Gold was better than Liquid Crystal?
Ah, it's too hard to say! In terms of pretty much everything (gameplay, graphics, new additions to the original story, etc), they're both equally awesome. I do agree with you, though, that considering what Zel had to work with back while Shiny Gold was in development - in terms of tools and general resources), he made something absolutely extraordinary. I mean by the time I played Heart Gold, years after Shiny Gold, I found myself absent-mindedly comparing the two, and in some cases I was actually happier with how Shiny Gold handled things!
Now I think of it, I reckon Liquid Crystal might've been the second hack I 'completed', haha. What can I say, I love Johto! :P