I mention
Disneyland because that is home base for me (first trip I remember was 1966). Eight trips to WDW over the last 11 years hopefully gets me past being considered a newbie.
I pay attention to details and differences and try to understand those.
My first trip to AK was about 2 months after EE opened. So I have no knowledge of what it was pre-EE but can imagine it was clearly a half-day park. Since I have started going there and pre-Pandora, we always found enough to keep us busy and on our toes from rope drop until 5 or 6PM which was near park closing. Even before Pandora I did not see AK as a half-day park but more of a lower effort park because it closed earlier than the other parks.
I do not know what you mean about moving the needle. You must mean something other than growing park attendance because AK has been growing (until last year when all 6 American Disney parks went backwards). AK is now the 4th most attended theme park in North America.
See 4th chart titled "American Disney Park Attendance Since 1991"
http://blog.wdwinfo.com/2015/06/06/disney-parks-take-top-six-spots-in-america-last-year/
2015 and 2016 data can be found here:
http://www.teaconnect.org/images/files/TEA_235_103719_170601.pdf
I am guessing here you must mean how many hours the average visitor stays in the park? That would be interesting data but I have not seen it. And I am not sure how Disney would know since they do not take data on people leaving AFAIK. Maybe you have more info on this?