Having owned a WRX for the better part of a decade, I was prepared for the fuel pump priming issue. Out of habit, I turn the key to ON (past ACC), wait for the needles to settle down, then wait a second longer, then crank.
It has been starting every time within two seconds. Entirely within the range of the WRX for 9 years.
All tanks standard 87 octane Union 76 or Chevron.
Temperature ranges have been between 20 degrees at the low end to 90 degrees at the high end.
Elevations have ranged from below sea-level to 10,000 feet / 3,000 meters.
Premium hatch, CVT.
What this means is open for debate, but at the least it means that the problem doesn't effect ALL 2012 Imprezas.