I think the best comparison so far was to Sifle-naught:
Dark Depths v Dreadnaught
-- Both fairly worlthless alone
-- Both suseptible to "small cc hate" (Repeal, EE, Deeds?)
-- Both can be tutored up with narrow, but situationally very useful tutors (Trinketmage v Crop Rotate).
- Dreadnaught is vunerable to artifact hate
- Dark Depths is vunerable to wasteland
Dark Depths kills an entire turn faster, however Stifle is more universally useful than Hexmage.
What people need to realize is that Dark Depths doesn't play like a Land, its an uncounterable

artifact, that doesn't count as an artfiact (and can be wastelanded i guess). To me comparing it to Orchard is probably less valid than to Ornithopter.
The fact that it IS a land makes it play like a land. It certainly doesn't play like a

artifact because you can't play it and a land at the same time. Ignoring the one-land-per-turn rule is basically ignoring everything that makes a land a land.
Here is why it's worse than Oath (if you want to make the comparison):
Best cards individually.
1) Stifle (actually good)
2) Orchard (produces mana)
3) Hexmage (at least a creature)
4) Dark Depths (literally does nothing)
Likelihood of God-Hand
1.5) Opponent has a creature + Land + Mox + Oath
1.5) Orchard + Oath + Mox
3) Lotus Petal/Black Lotus/Mox Jet + Dark Ritual + Dark Depths + Hexmage
Dreadnaught has a similar comparison, focusing on the ease of comboing (2 cards land + mox) and having better individual cards (stifle-hexmage-dark depths-dreadnaught).
As long as the combo is a *functional* win, the details are just details. People ran STP all the time to answer Tinker, but it was still run. People run Sphinx (or Inkwell) often over DSC even though they are slower. I pass them off as just details, because that's the interactive part of the combo, so you never know how other players will adapt. Not that they are trival, but just that they are too speculative at this stage for useful evaluation.
If you really want to compare it to something, I'd compare it to Tezzeret. 2 cards, one completely worthless, the other with marginal utility, but both relatively cheap. It avoids Null Rod, but is relatively slower to play (requiring colored mana) and to win (always must pass the turn).
The thing is it requires colored mana, i.e. reliably only with land drops, and that color isn't blue. So that means it doesn't really fit the Tezzeret shell. I don't think it really fits in a Dark Ritual shell either. Ritual decks are more bomb-decks not combo decks. Rituals aren't really combo pieces, they just functionally become moxen in compressed time-periods.
I don't have my own list, but looking at Judas list I would cut Rituals for moxen, go 3/1 Hex/Depths, cut Force, go 8 Duress/Thoughtseize, go Negate over Spell Pierce, cut DConsult, cut MisD, add Yawgwill, and a Tinker win-con
Rituals for Moxen.... Getting Negate up or Confidant online is more important that casting Hexmage and hopeing.
3/1 rather than 4/2... With tutors 4/2 is pretty excessive, imo. Too many hands with Depths or too many Hexmages.
Thoughtseize over Force... you said yourself, too few blue
Negate over Spell Pierce.... why open with blue when you can just Thoughtseize? Negate is better late game because it can't be paid off, which is why you need it.
no DConsult... when you have no other win con, losing it sucks
MisD... obv not if you can't even support force
Tinker... don't be averse to getting hit by confidant.
If you're not running Ritual, probably not a great idea to run sacrament. In my opinion, looking at your list it feels like you are running it more for sacrament then anything else. Though I have nothing against the card itself in this build, but it'll be too slow without ritual.