I've worked at 7 GM plants, all union. The only time I had long breaks was because management was bad at managing time. I can't think of a time I had a long break because of the union. Why would you have a long break because of the union? The union got us two 20 minute breaks and a half an hour lunch. If you call that long, then blame it on the union. Just like any other job, it's the boss who has to do the work to get the slackers back to work when the break is over.... Like I said, there's a lot wrong with the unions, but long breaks are managements problem....
Like I said, never done it so I don't know the full story, but these are my observations of local facilities that are union. They maybe abusing the system or it could be poor management, I don't know. With my job I have had the ability to observe every type of business over the last 10 years.
When we work at the American Airlines hanger we would only get in about 4 hours of work. The reason is that we had to be escorted around and could not touch anything with out them. They had a "I just got to work break"(8-8:30), "pre-lunch break"(11-11:30), lunch(11:30-12:30), "after lunch break"(12:30-1) and a "fixing to leave break"(3-3:30). This is what we were told by their employees and maybe they are abusing the system, I don't know. But I understand why American Airlines is in bad shape, a least by working at some of their local facilities.
Now at GM Arlington I've seen the same employees in the break room all day watching tv and on the phone. I've seen a guy punch holes in the side of a new Tahoe shell with a forklift and laugh about it. They ruined one of our scissor lifts out their by punching a hole through the battery box and batteries. One of GM's big executives was friends with one of our sales guy and together they "laundered" over $100k of fake service tickets and split the money. Maybe it's the management.
Now on the other hand, when I go out to Peterbilt assembly plant it's a different world. Those are hard working, well organized and trained employees. Have yet to see a slacker there over the years I've been going.
And just to make it fair, my company is probably one of the most corrupt businesses out there. Remember Dennis Kozlowski, I work for "that" company. We have been very close to have a monopoly on the industry several times. Guys used to be home before lunch time everyday. Then they put trackers on our trucks to "watch" everything we do. It is an automatic system that sends an email to our boss if we leave the house after 7am, get home before 4pm or drive faster than 75mph. It knows when you turn the truck on and off. Everything in between they have to watch. I don't think it's that bad as long as they give me enough work to do for the day.