this 
is very powerful if all 5 members in your team have it and constantly place em and combined with 
your gonna get 100% visions in less than 10mins after a mass planting
details about it: pro's: it has a very large cast range it has unlimited duration it doesn't have a limit on how many can be placed in the map
con's: enemies can see it if they walk on it enemies can one shot it a its very fragile
yeah, is OP I buy it a lot now, idk why but not everyone knows its so OP.
This item is actually amazing, but i never see anyone ever use it.
pretty easy: they forget to buy it(atleast my reason on most games) I'm just so used to yellow trinket that i forget to pick up the blue one at lvl 9 - which leads to the other problem: It requires to be lvl 9. If i could pick it up from the start, i would always take it, even if it had the same range as a normal ward and 3 min cd at lvl 1, just so i have it for sure at lvl 9. If you could kinda pre-buy it, so it automatically upgrades at lvl 9 to the farsight alteration, it would be awsome.
But right now, i often have different things on my mind when recalling post 9, and once i use my trinked ward i'm like 'dang, why didn't i switch that shit', just to forget it on the next back already.
The main problem is that enemies can kill it, so if you want 100% vision, 10 seconds later their jungler has cleared half of them.
