I have only anecdotal evidence, but I have found recruiting people to Magic is always easier when you let them build their own deck, or at least choose/open their own precon
If you do, you gain 4 life, draw four cards, put four +1/+1 counters on him, and he deals 4 damage to each opponent
So, if I activate Teferis +1 ability, he gets another loyalty counter, in addition to the abilitys other effects
Although lower in value compared to the next list we have below, the median price of these cards is still a lot higher compared to the cards that you'd usually find in regular sets
Aside from just filling your hand with more great Knights with this trigger, it can also be used to find powerful cards like Sword of Feast and Famine and Animate Dead