It's okay, but it's not Fallout 5. The fundamental problem is that it is, well, an online game. So even though not all of the game is oriented around online play, you can't do things like have the world change much around the player's actions, which was a major element of, say, Fallout: New Vegas.

I played through it, played it mostly as a single-player game, didn't regret the purchase, but do regret that Bethesda decided to do it instead of Fallout 5.

It's Fallout 4 with some engine and mechanics improvements (e.g. Fallout 4's bonkers dialog system went away, and it works like earlier games in the series) but a lot less nice single-player content.

I think that the person who is gonna enjoy it the most is something like people who just want to kinda casually mess around with friends or a spouse in a Fallout-themed world, want to build camps in 3D for aesthetic value. It's definitely the easiest Fallout game I've played.

And it can't be extensively modded, because it's online, so the modding crowd is kind of out of luck.

I hope Starfield modding takes off, because Fallout 5 isn't coming anytime soon. Maybe we'll get something like Tales of Two Worlds in Starfield (TTW meets Fallout 4?), because the Starfield engine does a much better job of streaming content smoothly as one moves from cell to cell than with the earlier games from Bethesda.