Eye of the Watchers vs Frost Queen's Claim

Let's face it, is almost completely useless. Let's see why is so much better.

First of all, assume you already have . Now what's the big difference between these upgrades?

Advantages of : +50 health +10 AP +50% base MP5 +1 max ward charge

None of these are particularly good. It's not even a very well-spent 550 gold when you only get a tiny bit of stats and +1 ward. Some could say that the MP5 is good, but since you already have +100% from the frost fang, 50% more really doesn't do much as you can already use your abilities in most of the times they are of any decent use, anyways.

But what do you get for upgrading to : +35 AP +10% CDR +50% base MP5 +A very good active that not only scouts, but also is a 40% slow for 4 seconds, which is huge in that it so often means you can catch and kill some retreating enemy.

So what's better, 550 gold for the first item or 1350 for the second? The second one gives a lot more usefulness per point of gold spent and is actually extremely efficient since it gives good stats and an active that is like a dream ability for a lot of supports profiding scouting, vision of enemy champions, and a very powerful slow.

I guess one could argue that only takes up one item slot, but from my experience, the game is likely over or at least decided before you'd actually run out of slots for the items you're trying to make. So that doesn't seem that relevant right now at least.

Is there some hidden reason to get that I just haven't thought of, or is it useless?