I guess let's include propaganda in this discussion as well.

Lot's of talk about moat recently, be it price or availability or uses in combating eldrazi. It made my wonder why we put such a high premium on moat to battle decks like eldrazi when I actually think ghostly prison and propaganda may be better options overall. Let's look at the pros and cost of Propaganda over moat.

PROS:

• 1 CMC cheaper
• Hits flyers like delve
• Asymmetrical, does not affect your creatures
• Can be pitched for force of will (Propaganda)
• Stacks with similar effects (thougth may not be relevant unless you hit targets moat can't)

CONS:

• Offers an escape clause with a high price
• Cost puts it out of range of Natural state which has seen occasional play

So looking at it this way, I understand why moat can be better against drazi, because they basically have 0 flyers for now so it's 100% no escape clause coverage for the deck, but when you consider that the eldrazi mana base really does not allow them to pay the tax to attack easily in the first place, wouldn't it not be better to have the cheaper option that can hit play before they can thought knot it away? The option that also prevents Delver and the odd Mantis Rider from swooping in?

Let's also not pretend like an army of monks is going to have any easier a time trying to pay 2 mana per attacker and then still have mana to cast spells to pump.

Honestly the power of propaganda makes me wonder if merfolk should not be a go to option right now. Run 4 propaganda, 4 True names, and a buncha counters for non creatures and go to town, but thats another topic.

So thoughts? Are flyers so irrelevant and mana so easy to pay right now that I'm way off?

The fact that Moat ends the game and doesn't just slow the kill is all the difference vs Eldrazi. It's not uncommon for them to have a tomb or any open 2 mana to smash you with smasher. Consider temple, tomb, Ugin in play...they cast a smasher and you've stopped their haste attack with your prison/propaganda...awesome. Next turn they cast thought-knot, then pay 2 from tomb to hit you for 5. Next turn they drop any mana source and smash you for 9. You can see where this goes. You might DELAY them from killing you for a few turns, and in the right deck that might be all you need. But if you stick moat, it's gg, no questions asked.

Additionally, if you are facing Mentor or pyromancer, they are screwed too. Yes, they are slowed much worse than eldrazi by a prison, but they can still pump the mentor with prowess and hit for 4-5 a turn, leaving the tokens up as blockers. Delver of Secrets is pretty much the ONLY flier in Vintage that people need to worry about, and there are more efficient ways to take care of him. Decks even run abrupt decay, which is another win for moat. Stopping dredge, mentor/pyro, eldrazi, GW fish (outside of pridemage) permanently and completely is what makes moat far better. The only other fliers are emrakul/griselbrand, and they don't give a crap about paying 2 mana to win.

If your deck can take advantage of the couple turn delay a prison buys you, then those slots could easily be plows and buy you the same amount of time with greater utility. Decks that run moat need a compact card that just wins and not just a double time walk.

Also, Propaganda doesn't protect your PWs.