E's have another belt, they're stronger. Inflate them to D specs and they're only slightly stiffer, but significantly stronger. I'd rather (and do) run E's when D's would suffice by the book. I inflate them 5 PSI over D specs.
Our first camper, a pop-up, came with LRC. While on a 6 week grand tour of the western US, kept blowing tires, 3 or 4 during the trip. We were fully loaded, but not over the sticker rating. First blowout was replaced with a LRD. After that, LRE. By the time we got back, they were all LRE, and no issues after going to them.