I know the dates for the start of the Iron Age differ by region, but let's take, for example, Europe, the Aegean and the Near East circa 1200-1000 BC. What would have happened when armies armed with iron weapons faced off against those armed with bronze weapons? From what I understand, early iron-working was of very poor quality. What innovations would have led to it superseding bronze for use in tools and weapons?

Was the adoption of iron uniform throughout specific regions, or were there holdouts that continued to use bronze well into the start of the Iron Age, despite almost certainly being familiar with the use of iron? Basically, I'm interested in all information about how the transition period between the Bronze and Iron ages played out.