Exhaust or Ignite .... ?

As a sup sometimes people including me have to decide which summoner spell to use or . Lats start with "Pros and Cons" (everything is IMO) Pros: 1.Grate early game kill potential. 2.Decrease healing effects => good vs healing supports . 3.Just by picking it , you put a bit of fear in your opponent bot lane . 4.Less tricky to use , to gain the most of it compared to exhaust. 5.Scales with level. 6.Grants vision of the target. 7.Can help champs that lacks early dmg to stay relevant until core items are bought.

Cons. 1.Can't be used defensively .( if you are both low and you are running for your life , ignite won't matter if you don't plan on fighting. 2. Can't impact one-shoting fed assassins if try to kill your carry. 3.Less impactful late game .

Pros:

1. Can be used defensively and offensively . 2.The best at keeping your carry alive. 3.Can be used to slow and catch up to people .(not recommended , good only if killing that target is essential ) 4.Shut down fed enemy burst champs and AA reliant champs . 5.Sometimes enemies don't take note if you exhaust them and they blow their main dmg spells . 6.Grate late game impact .

Cons. 1.Good players know how to deal with it. 2.Need to be used at the proper target at the right time . (Exhausting the wrong target or at bad time may coast you the game.) 4.Not as good as ignite early .

Feel free to leave your opinion on the topic or if you think i forgot something :)