PVP or VS AI?

After a certain level, you get reduced ip and pretty sure xp too from bots. Play rotating game mode when its up, or aram. They're faster

you could also play Twisted treeline, same xp, same ip, shorter games.

Bots games are more consistent XP since you're always winning but PvP game give more XP for a win; losing PvP games though gives XP slightly less then a bot game.

If you have a champ you feel really comfy on to take into PvP as to where you'll win more then you'll lose, PvP can be more XP.