Like Sokka's bommerang, you knew it'd come backFollow

The difference in my opinion is that Aang was 5 years younger and barely had training in his non-native elements. He had less than 1 year of water-bending training and maybe 1 month of fire-bending. Whereas Korra is now 18 and should be a master in everything but air.

But you have a good point about Aang's stronger spiritual connectiong giving him a stronger avatar state. Korra often did the thing where her eyes glowed like she was going into avatar state, but she only got a short boost of power instead of going into god-mode.

That's how the avatar state's meant to be used; a brief boost of power, so as to minimise the danger of permadeath. Aang goes all crazy when he avatars up because he isn't in control of it.

Just gonna point out that we see Aang use the avatar state to break out of some bloodbending in S1 of LoK. He didn't go into some crazy god-mode, he just accessed some additional spiritual power, and nothing about the next bit of bending was anything like his childhood Avatar states.

Aang in the original series usually went into the avatar state because he lost control, and was channeling the combined fury of the past Avatars. It was fueled by his rage, triggered by his anger, his fear of death, etc.

The only time it was super controlled, that I'm remembering off the top of my head, was when he fused with the Ocean Spirit Tui. And that wasn't about Aang's bending, that was about using the spirit pathway to channel Tui's power, from what I can tell.

Also worth noting is that you saw a lot of Avatars using the Avatar State in the first series in montages. And it was usually just a quick flash of the eyes followed by a bigger act of bending (like a much bigger rush of wind, a bigger wave, etc.).

Aang usually succumbed to the avatar state, he didn't really use it.

And a big part of that, I think, is because he was so afraid to use it. Instead of getting a quick burst of energy in battles, he did the attrition thing until he was forced to go full-on avatar state to survive.