When my opponent draws a card from Journeyman and I know what it is, now it shows me the card face up instead of just the back of the card. I haven't tested this with all reveal cards but I'm pretty sure it doesn't happen with Crossroads.
If this is going to be an option at all, I feel pretty strongly that it shouldn't be the default option. It's a similar argument for point counter but I'd say the default for that should be off as well.
If you're going to make this a feature, though, it needs to be perfect and completely consistent. Right now, face-up cards cover face-down cards so it's hard to tell how many cards are in hand, and then there is no way for the opponent to easily see which cards are revealed to their opponent so that those are played first -- this would matter for Envoy especially.