Substitutes: What are your thoughts on it?

[MisChief]

Yes. I have one in my reserve. This was my observation from my own experience. It even dropped in during banish. Until i took it out. This is not speculation or assumption.

And about the Wed chests purchases, BETA still can't buy gems, so using 100 on a chest is a rare sight indeed. And it remains to be seen how this may affect live, but from all i have heard and discussed with fellow players, they'd rather have stamina.