It's worse than a lascannon at killing armor. Even if you're literally touching the back of a rhino and firing it takes overheating it at least twice to blow it up. Hilariously easymode vs doods though.
It doesn't seem to be that OP from my limited experience. It's probably worse if you're playing as a melee character, but as a ranged one I can't say that I was killed by Meltas that often.
Hows the FF on it? If it's as nasty as people are saying, I imagine lots of friendly kills/blinding heh.
I really liked it. Great at dealing with melee units charging head on and unsuspecting ranged enemies. Takes some time to down armor but you can always use the Lascannon if you want to drop a Predator fast.
As I said, my experience was limited, but I don't feel like it's even close to the initial Storm Bolter level of OP. Granted, it does seem to be a bit harder to fire than SB was, so it can become much more annoying once people get the hold of it.
It should have a windup time imo, even if slow. Its supposed to be the end tier AV weapon and its more then formidable in the AI department. And yes im very much aware that melta eats everything alive, but the weapon itself has to be allot more unwieldy for something pumping out that damage. Perhaps the mouse sensitivity takes a dive once you actually start firing it, to simulate how its hard to handle it. Would also help balance it imo.
To all the devastators worried about anti melee, can you imagine the multi melta at close range? I'm smirking already...