Normally, Standard rotation removes older sets from the format once per year
Then you can spend four mana at sorcery speed and then you can cast creatures from the top of your library which is great in decks with a big creature count, and you can set your library up with cards like Sylvan Library and Sensei's Divining Top
Finally, there are a couple ways to turn +1/+1 counters into direct damage without attacking
As token makers go, things like Decree of Justice and White Sun's Zenith (two other cards many of you mentioned) will ring as stronger, but none will draw as many laughs as Flock of Rabid Sheep
Where this does jump in power is in combination with things like Pitiless Plunderer, Pawn of Ulamog, Crytolith Rite and Ashnod's Altar
Every card has a set it belongs to, the numbering is built in, and it maps directly to how the TCG is actually structured