In my experience, the performance of the News app can vary quite a bit. I assume they are making frequent updates on the back-end of the system. When the News app first came out, it would only update the articles once every few days, now it updates them throughout the day and crashes a lot less often.
I've noticed several publications (CNN, ESPN, NYT, Reuters, Bloomberg, Vox, Atlantic, Slate, Quartz, Buzzfeed) have started using their own custom Apple News Formats with some looking significantly better than others. Others, such as NPR, Fox News or MSNBC, still operate as RSS readers where you just get the headline and then pull up to be taken to the website. Finally, there are a few publications that are no longer posting new articles, WSJ and Guardian are two. It could be they intentionally disabled it or that they are preparing their own custom format.