Change IBG and FIX this 3 item meta
Okay so Riot clearly recognises this item packs wayy too much power. Their PBE changes are to change it's spellblade effect from 125% base damage to 100%. This will solve NOTHING. Here's why:
The item's stats, in order of importance are: armor, AOE slow, CDR, bonus spellblade, mana. This varies for different champions of course, some really love the CDR more and some make more out of the AOE slow and mana (Ezreal...).
Now, there is a very similar item to frozen gauntlet already in existence. That item is 
.
Differences between item? Iceborn has aoe slow, bonus damage, 100 more mana and costs 100 LESS. Frozen heart has 25 more armor and attack speed reduction aura.
It's quite amazing that gauntlet costs 100 less despite the other added bonuses. In reality, players love the item more than frozen heart because of the AOE slow more than anything else. This allows them to stick to their target, cc lock them more and with this do more damage through sunfire and their abilities. This item is simply broken as it stands currently. Here's how I propose to change it:
+ 
+ 
+ 450 gold (total 2600 gold)
+75 armor
+400 mana
+10% cooldown reduction
Passive
UNIQUE – SPELLBLADE: After using an ability, your next basic attack (on-hit) creates an ICY ZONE under the target for 2 seconds. This zone has a radius of 140 (+ 70% bonus armor) units. (1.5 second cooldown.)
UNIQUE – ICY ZONE: Deals 150% base attack damage as bonus physical damage to all units within the area of effect and slows them by 15%.
I think this will differentiate it more from for starters. If you want to go full tank, surely an item that gives purely defensive stats should at least be a consideration. Gauntlet will now give a bit more armor, less of a slow and less CDR. It also does a little more damage, so it is clearly a more offensive item that can't just be abused for it's perma slow. This is the only way to fix the item beyond nerfing it to the ground.
BONUS: this would also stop Ezreal abusing it so much too.