So fans of the Show Avatar the Last Airbender: What did you think of the technology progression over the 70 year time gap between ATLA and LOK? Did you like it? Hate it? What was your opinion on it?
I watched all of ATLA and the first several episodes of Korra (so far). I find the leap in technology fairly jarring. I suppose that kind of advance is possible in that time, but it seems so dramatic. The Avatar world doesn’t seem quite as magical anymore. 
Avatar had fairly robust steam technology, or at least the Fire Kingdom did. If we set the steamer navy they had at 1850 or so technology, that puts LoK at 1920s technology, which is what we see, more or less.
I think it seems jarring, because it would have been jarring to anyone who had experienced both times.
ATLA had tanks, airships, battleships, and that large screw machine. Powered by fire magic, but they had it.
Korra’s technology is mostly fine but is a bit schizophrenic. They barely have the beginning of film, they have biplanes…but they also have mecha battle suits made out of platinum.
It felt pretty natural to me.
If you assume that the Avatar world’s technology would advance at a pace roughly parallel to our own, or somewhat faster thanks to the existence of bending (so people can more directly manipulate materials and energy sources), then we basically move from the equivalent of the early 1800s and the very beginning of industrialization to the 1920s, which is the clear analogue of the Korra era. Presumably the peak of the Industrial Revolution passed in the middle years. Also, since Korra is largely focused on Republic City (the “New York” equivalent of the Avatarverse), we’re seeing the most urbanized and industrialized citizens of the Four Nations. When we venture out to the Water Tribes, we see people living in environments more similar to what we saw in A:TLA, with a more subtle upgrading of their technology. Which is pretty much exactly what you’d expect.
If anything, the “inconsistent” period would be the A:TLA period, when you had mecha-tanks in the Fire Nation fighting alongside squads of archers. But that’s readily explained in-universe by the use of firebending in powering both the tanks themselves and their armament.
I think that’s also easily explained by the influence bending would have on their societies. Firebending is clearly the progenitor of the steampunk technology powering both the biplanes and the battle suits, but understanding flight itself is something that would’ve been limited to the airbenders… who are somewhat lacking in numbers (and those who are left don’t seem terribly interested in engineering). It’s one thing to translate your firebending into development of electrical power. It’s another to discover Bernoulli’s principles de novo.