Has anyone heard this series yet? How does it stack up to classics like "Mysterious Traveller?"

It has some good episodes. House on Lost Man's Bluff is especially good. Avoid Story Without End like the plague. I understand that William Conrad and John Dehner were regulars on this show. There's a plot summary section for this show at OTR Plot Spot (the link's at the bottom of the main page here).

I think there was also an OTR series that was hosted by a witch. Characters such as this were the obvious inspiration for Bill Gaines to create his own creepy hosts for his classic comics, like the crypt keeper.

That would be The Witch's Tale. I have a tape with two episodes and they're not bad.