So... mom's heart...

[Nicholas Steel]

I beat it, went in to the Angel Room expecting ya'know, a typical Angel Room and instead it takes me to a new level... so I never got the massive gold treasure chest :/ (Afaik the giant treasure chest took you to a treasure world in original Binding of Isaac)

I'm dissapointed in the unintuitiveness of this.

[Nazemec]

What would be the point of getting an Angel item if you end your run at this point (touching the chest) ?
Byt the way, check your "endings" menu (in Stats), I think you still unlocked one. You can see it there.
And don't worry, when you'll have a permanent access to the Cathedral and Sheol unlocked, the Angel/Devil room will be a normal one (without a trapdoor or beam of light). If you have Afterbirth though, not sure if it was changed in Rebirth.

[Nicholas Steel]

It's not clear that the giant treasure chest will end the current run and it wasn't clear that the circle of light in the angel room would warp you to a completely new level either. Thankfully I was suped up enough to easily best every room in the Angel area and reach... another giant golden treasure chest which immediatly ended the current playthrough when I touched it.

So in the end I made the right choice of going in to the Angel's light as the giant treasure chest would've immediatly ended the game? I'm sure there was a treasure chest world but maybe I'm wrong?

Uhm, also since I beat it I don't get a Seed to use if I want to replay that... well, on to the next playthrough I guess now that I unlocked a bunch of stuff.

[Nazemec]

There is a "chest world" (The Chest level), but you're still far from it. You'll have to beat the Cathedral 5 times to unlock a specific item, take this item (dropped by Mom's foot), and beat the Cathedral again to enter the Chest. There's an equivalent path in Sheol.
There's no really "a right choice", only different paths.

[Nicholas Steel]

kk, so far Afterbirth seems to have fixed a lot of what made Rebirth boring as ♥♥♥♥. The new items, room designs and especially the new large room designs and enemy designs just make for a much more fun experience. in Rebirth I always dreaded the large rooms as they were so incredibly dull and the items just weren't that interesting, it was worse than the original retail Flash game.