I like Rebuild quite a lot overall. The standard Rebuild thing is a unique deck in Dominion. It's a bit boring but still has some deck composition choices, deck tracking stuff, and interactive/endgame VP stuff. I can appreciate playing it in the uncommon cases nowadays that you both see Rebuild and that deck looks good. The fast pace is nice.
Rebuild's low level of interactivity with other kingdom cards has at least one upside to me, it can result in very divergent decks if people don't mirror. It's fun to see games where it's the kingdom vs Rebuild. People probably hate this about it, but the fact that Rebuild with decent draws can put pressure on a lot of decks can add some tension to games, even when Rebuild is not very good.
I wouldn't want to play it as often as you did when Dark Ages released, but in this card pool I'm a fan.
Once in a blue moon you can roll a board where the VP upgrading is good engine payload and you have control of what the Rebuild hits through discard stuff or whatever.