They’re very theatrical all the time, IMO, but as I said: I’m not a fan. Bruce Dickinson has a helluva voice and he loves to use it; so do his mates and Iron Maiden’s fans, so he does. His voice is definitely one of the standout things for the band, but he never stays too long in power metal territory, thankfully.
In my head, Iron Maiden and Judas Priest are indelibly linked as pretty much the top of NWOBHM bands, and I like that I hear so much similarity and so much difference in their music. They’re shufflers for sure, but their songs that I like get turned up when they start moving air.
How about some history? Let’s talk about proto-metal!
Back in 1969, a young guitar player named Richie Wise met a couple of even younger teenagers who could play bass and drums, Kenny Aaronson and Marc Bell. They formed a band called Dust that released 2 albums, an eponymous debut in 1971 and a follow-up called Hard Attack the next year. They broke up soon after, tho, because Wise wanted to write songs and produce records rather than perform; Aaronson would join him in this endeavor and a short time later they helped usher in KISS by producing their first two albums and writing a few of the songs therein.
The drummer liked performing tho and continued his career with a number of acts for another 5 years, including a stint with Richard Hell & the Voidoids, playing on their first album. In 1978, tho, he became known to all as Marky Ramone, a name he would carry for the next 15 years and the name he is still best known by today.
Anyway, Dust was known for being heavy and fast. Marc Bell says on the 2013 re-release liner notes that Richie just kept making him play faster and faster with every take; he couldn’t believe how fast he was playing! This was 1971, mind. They don’t hold a candle to a lot of metal acts today, but for their time, they are pretty up-tempo. The songs are good, too; Richie Wise is a capable tunesmith and player. Aaronson’s bass playing is solid, too. Check out Dust - Love Me Hard.