User blog comment:Veryverylongname/Who's is the bot lane leading role?/@comment-190.55.254.56-20130308084529/@comment-216.36.26.248-20130319142512

Sorry for the delay. Nami and Sona both have surprisingly similar kits.

Nami's passive grants a speed bonus to her allies any time she casts a spell on them. Sona's E has the same effect.

Nami has a stun on her Q, Sona can slow or get bonus damage with her passive.

Nami buffs damage with her E, Sona buffs damage with her Q.

Nami's heal is a longer cooldown, but heals for more and bounces to enemies for bonus damage.

In the end, the reason I prefer Nami over Sona mostly has to do with the range on the Ult. Nami's has a delay in hitting the target, unlike Sona, but has considerably more range. Nami's ult is also a knockup, which is not reduced or avoidable by tenacity or Cleanse.

Nami is a bit more mana hungry, but with both characters i build chalice of harmony and the problem disappears anyway. Just need to be more cautious early game.