1. The five dual lands in this set should have been more powerful than these. As it is these five rare slots are junk rare slots.
2. These could have been issued as uncommons and they would have been highly sought after at that rarity level for all types of Scry 1 shenanigans.
3. It looks like the shock lands will increase in price given the alternatives in Standard are these S(cry) lands and the Guild Gates.
4. I will feel cheated if I pull these in ANY format (sealed, draft) because I would rather pull a real rare in that slot.
5. These ALWAYS enter the battlefield (ETB) tapped! ouch!
And these are my opinions that lean to the positive:
6. These dual lands will likely keep Theros booster pack prices within a reasonable range. The whole set has not been spoiled, though. Yes, the set has Thoughtseize, but at rare, this card alone will not turn this set into the Thoughtseize lottery.
7. M15 and/or the next block will likely have higher quality dual lands at rare.
8. Standard will be a slower format during at least one whole year, and I like a slower format.
9. Mono-colored decks will be viable.
10. Many cards have not yet been spoiled that these lands can have good synergy with.
11. We have not played with them to find out how good they are.
On balance my summary opinion is very slightly negative and almost neutral, and that is probably the consensus opinion the designers were aiming at (you got the shock land reprints, now pull these mediocre lands and shut up, they probably thought).
