Yeah, I played it a lot more tonight, taking it 4-2 through a Traditional Constructed event, and then some ranked play, and it's super fun. And also seems to have plenty of game vs most decks. I really like having the Expansion half of Explosion in there, since it can do a lot of work defending your spells vs counters, copying draw spells, or other random things that come up. And the joy of Niv Mizzet + Explosion, even for a reasonable amount like 4 or 5, cannot be overstated.
I definitely lost some games doing some dumb stuff and forgot SO MANY times to set the stop in the end step that lets you float mana with Reclamation. I wish I could put a dice on my digital deck to remind myself of this. I'm at least trying to always set a beginning turn stop as a sort of "did you set your end of turn stop" reminder. But if you don't have it set when Reclamation is resolving it might be too late. Which is super annoying, so that got me a lot. Sure would be nice if you could just set a permanent stop...