The Letters of J.R.R. Tolkien: Revised and Expanded, UK and US edition comparison

Thought I'd compare the two new editions of this amazing book, if people are on the fence, or are not aware there are any differences. By the way, forgot to mention but the US edition feels a lot lighter than the UK one, but I hope i demonstrated that by managing to hold it in one hand. Also, I'm not sure, but the stiff binding on the UK edition may mean it will stand the test of time better, maybe looser binding could mean the pages are more likely to fall out over time, who knows - just a thought.