So I recently got into the Heroes of the Storm beta and tried a few games. After a while I earned enough gold to unlock a new hero - when in the shop I found out they have a 'try' button for heroes you haven't unlocked yet.
Simple, yet effective.
Basically when you 'try' a hero you are put in a 1v1 testmap (sort of like ARAM) and you get some extra buttons to 'level up', 'toggle minions', 'reset minions and tower damage', 'reset cooldowns' for testing purposes. Obviously this won't feel like an actual game, but it does give you a good idea of how the hero plays out.
It seems like something that wouldn't hurt to be added to League.
Perhaps in League for testing purposes the map would also need to have a jungle, but the simple fact remains that if you can try a champion a bit (without it having to be in the free rotation, but simply to see if you like the feel of it) you freely can do so. So you don't blindly purchase a champion without having any previous knowledge about it - other than - he looked cool!
What do you think?