For example, if youre building a deck around Urza, Lord High Artificer, you probably want a ton of cheap artifact creatures you can tap for mana, and then big heavy hitters you can cast with his second ability and all of that mana you generate
Then Vinticards.com is the right place for you
However, the whole having-to-wait-a-whole-turn-cycle-to-use-them is a real downside, just not one massive enough for me to knock one of the best Black cards of all time, both in and outside of cEDH
Atemsis, All-Seeing I have fond memories of trying to win with Atemsis, All-Seeings ability in M20 drafts, then realizing my opponent just dies to a few 4-power swings first
Providing one green mana for each creature you control, Gaeas Cradle is always useful and gets absurd in the right deck