The game is going to be a ton better.
Will it come close to OnC?
Not at all.
Similar to this game, it's a smaller developer. And when they released their game last June, it arguably wasn't much better than an Alpha. But they released it, and the company and the community endured and slowly fleshed the game out. Now after a large number of patches, and a few Updates, this update 3 will be almost a legitimate re-launch of the game.
Which to me is a smart move. You can't continue to proceed when the graphics look like EQ 1 but 20 years later. I can't say that it will be the game for everyone, nor can I say that the mechanics are completely different. Some of the things you hated before, you will continue to hate now

But so much of the clunky-nature and the overall lore of the game is repaired, reconstructed and made worthwhile. And the update provides an entirely new engine which can be patched much much more frequently. Even Updated more frequently.
Is it worth checking out? Personally I think so, but given that the Update was shipped to Apple about 10 days ago...I still expect a good week till it makes sense to check out. I think for people searching for a filler between whatever yer playing now and whatever yer waiting for to play...this could be worth it. And like WoM, it's free to try and either tell everyone you hate it or wiggle yer toes in the water and see.