It's a perception thing, that's what I see being the issue here. Player mentality will, in the end, define whether Mana Adapt is fun or not. It's the whole "the glass is half full" "the glass is half empty" comparison. Blizzards version required you to look at mana gains as an extra +spellpower trinket.

I will disagree with any blanket statement claiming that a specific side of your mana bar makes this ability more fun.

The proposed version has the potential to frustrate a lot of people on long fights.
The reversed version will frustrate players on short fights.
Both versions will be frustrating in the new version of PVP.

The last point is very important, and is the key reason why the current proposed version of MA is flawed.

PVP combat will be significantly longer in comparison to what we have now. In this sense, the reversed MA is annoying because, unless you're fighting people that think using a mana drain on you is a good idea, it's either take a long time to reach your potential or you'll be reduced to just spamming Arcane Blast just to get your mana down.

Blizzards version, however, makes mana drains very appealing against a mage, and since the battles will go on longer, being stuck at low mana will become a burden that no ammount of mana-management will solve.


But back to PVE, the reversed MA concept would potentially be very very boring. Imagine arcane mages doing nothing but spam Arcane Blast until they're below 50% mana. A 2-3 button spec becomes a 1 button spec. That's not fun for most of us, no matter how big our numbers get. You'll also be limited to mid-range length boss fights. Anything shorter or longer that you're potency duration and you're suddenly gimped.

Both versions are flawed for various aspects of the game. Both can be perceived as not being fun. Blizzard's is more appealing to me at the moment, but until we know the thresholds, I wont commit to saying it's the correct direction.