Originally Posted by Cauldrath
The problem with Hexdrinker is that it leaves you with the question of what to build for armor if you aren't grabbing Atma's. If you're playing a mana-less AD caster, your armor options aren't exactly great. It's also another mid-cost option when there are so few good high-cost options and so many good mid-cost options that slots are more a limiter than cost. For Riven, this is why I buy Aegis, so I can get armor and mr in one slot, and why I only buy Prospector's if I think the game is enough of a stomp that I won't fill my slots anyway.
Thornmail, Aegis, Randuins (seems to be overlooked a whole lot), Guardian Angel, Sunfire Cape.
The only things excluded are Glacial Shroud/Frozen Heart, Emblem of Valor/Locket, Ninja Tabi, and Hourglass.
Indeed slots area limited. That's kind of the point of only having 6. More like 5 since boots are pretty much mandatory. That's the point of thinking out item builds.
One day RIOT will be adding a whole slew of new items, just you wait. But I do think Hexdrinker is fairly weak as a damage item, and is a great defensive item. Wish there was an AP version with that proc. Abyssal Scepter is nice though.