Well...that's probably one of, if not the best uncommon in the set for limited. It's going to take a lot to beat 3 damage to any target and draw a card/rummage for 3 mana, even with it only being sorcery speed.
The more I think about this card, the more I think this has stiff competition with Bonecrusher Giant. Although Bonecrusher Giant's burn end deals only 2 damage, it's at instant speed, and not many Lessons can outdo a 3-mana 4/3. How much will access to mass looting, (expensive, drawback-prone) removal, or a guaranteed Magecraft/Prowess trigger be worth?