In my opinion, it's cool, but it could use some more power in it.
The 40 AP is barely anything. It's a good amount for the item, but looking at that number '40' in the shop, it really makes you not want to buy it. If they were to buff it's AP to 50 or 60, it'd be a lot more appealing by looking at the numbers.
But other than the low AP count, it's a good item. The passive for it is really strong for an AP jungler, but very few are AA reliant which is what the item tends to lean toward. I went in a custom game as Fizz and I was clearing the camps really quickly with an E and a Q, but other junglers have problems. Diana would work well with it because she has a ton of AA's thrown out when she fights, but pure mage jungers would have probelms with it.
The 10% cooldown reduction is a cool bonus. It's not the old 20% of Magus, but it's a different item.
I sort of have a problem with the item is the mana sustain. It's not terrible, but it's not really good. 8% missing mana restored isn't terrible, it's actually good when you're on low mana, but when you're at a higher level of mana, it's not so well. I'd think a good, flat 6% max mana restored would be cool and really strengthen the item, but the 8% missing mana is balanced.
So, they should really just increase the AP it gives so it looks more appealing on paper, because the item is pretty good in itself, but it's AP isn't visually appealing.