From my roughly 20 games of the new TT, I've felt like the Grez's Lantern item active is incredibly lame for about all the same reasons you said Lightbringer is lame. It's an even dumber reveal than Lightbringer as you can activate it from like 1500 range, much farther than auto attacks. The fact that stealth champions get revealed for the entire 10 second duration REGARDLESS of whether they stay within the area or not and REGARDLESS of whether they were within the the initial blast or if they touch the circle(which is poorly communicated to the player of where exactly the edges are with just those sparkles) at the very end of the ten second duration, is just detrimental to all champions with a stealth mechanic. Bruiser style champions were already dominating, but when they buy this item 5 minutes into the game, it totally gimps an enemy Shaco/Rengar/Talon by removing a gameplay element from their kit that they're balanced around relying on. Shaco needs to play knowing he has a reliable escape, but as soon as the enemy has Grez Lantern, his kit gets severely nerfed for the duration of the game.
Designers have stated they shy away from in-game counter strategies that hard counter opponents severely to the point that they have no answer and are doomed to be weak for the rest of the game. Well, the current implementation of Grez' Spectral Lantern annihilates the overall usefulness of someone like Shaco in an item active that costs less than 150 gold. (150 gold gives 7 armor, 10 AD, and the active). Preposterous!
(I played about 5 games as Shaco. The only one I was able to carry was when the enemy didn't buy the lantern)