Baically, I think the purple vision ward needs a rework. Yes, the ward need a rework.
why? Because if you use a vision ward to remove another ward, then the enemy sees you place that ward there anyway. It's like revealing the vision wad for the sake of also destroying an enemy vision ward. Naturally, enemies will know for approximately how long it will last there. It is also a hard counter for champions like wukong and twich(perhaps even evelyn) to just pop a 125 gold ward in a bush or the middle of the lane and destroy their skillset for a quarter of the laning phase. That's why I think it needs a rework.
So this is what I proppose(please excuse my bad english.):
Lower the time it takes for the vision ward to expire. It should be primarily used just for clearing wards and other special situation, not placing a sightward AND getting vvision of all the other wards in that area. Somewhere to around 15 to 30 seconds might be a good idea. This is to make it feel like you are not warding, but actually counterwarding. The ward is thereto remove other wards, not to give you vision of that area. It could also be used for quick situations like checking the bush for teemo... anyone?
Reduce the cost. This should be done only if the wards lifetime is reduced because a lesser period of vision means a lesser gold cost. It should, however not exceed the combined value of the sight ward. Thus if one vision ward costs 100 gold and gives you 1 minute of vision, then that's pretty much ****, cause it's the same thing as a single vision ward costing 75(plus repositioning options).
Perhaps make it explode uppon expiring. There is really no reason to do this, but it would be fun to have it dewal like 100 true damage in a small aoe to someone who is near it when it runs out. Just for the lol's.
So, thank you for reading. Please tell me your opinion on the current method of warding - counterwarding within the game. As a twich player(on EUNE, this account is just for the forum) I find that pink wards and oracles(discuss that too) area really op, since I often rely on stealth to reposition myself. Thank you!