My experience going through security has always been much smoother than when I traveled to the US. Lines are smaller, security is more relaxed (never had to take my shoes off for example) and the security staff for the most part are much kinder.
When I flew through the US (arrived at DFW to connect to SFO, drove to LA and went from LAX to JFK) I think the only airport that everything was smooth was SFO. DFW was meh-ok but I had to go through immigration so don't want to consider it. But oh my fucking god, I pray to never have to go through LAX again, never expected to be treated like cattle with rude agents everywhere. JFK was a little bit better but not by much.
So yes, comparing my experience between LAX, SFO, JFK and DFW against ARN, MUN, TXL, SXF, BCN, FRA, CDG, AMS, ZUR and DUB... There's really no comparison, never felt mistreated or had any kind of problem with security staff or time in the queues in any of the European airports.
In every case the security involved an X-ray for luggage and walking thru a metal detector. That was it.
Australia in 2014 otoh was nuts. I was taken aside and magic wanded at one airport, subject to a personal body scan (???) and patdown at another, and interrogated on my way out (apparently "company employee" was not an adequate description of my occupation).
Combined with other security theater like police leading dogs around at the gate, it made me not want to visit there again. It was scary!