I just want to add, that 1-mana ramp dorks do fit ower power levels. As japahn already stated, power level is not a number, so you can balance the whole cube in a way, that these won't lead to overpowered stuff. I run BoP, Llanowar Elves, Arbor Elf, Boreal Druid, Wild Growth and Utopia Sprawl, despite my pretty low power level. The idea is, that these won't harm the environment when they ramp into Ondu Giant instead of Garruk Wildspeaker and then into Rhox instead of Carnage Tyrant or whatever broken 6-drops kids run these days.
That being said, I don't think they scale 100% completely with the environment, as it is important how quickly other decks can add to the board.
That being said, I don't think they scale 100% completely with the environment, as it is important how quickly other decks can add to the board.