A brief Kindle update after not quite 48 hours' use:
I've read my first book on it (it's a lovely one!) and downloaded a second.
The dictionary function is great, as to look up a word while you're reading (you can access the dictionary itself directly, too), you just put the cursor next to the word and up pops a brief definition; press another button and you have the full entry.
Dark Puss suggested getting the free Kindle app for PC, and I've done so this afternoon and can now manage all my notes and bookmarks easily, something which will be particularly helpful when I come to write posts about Kindle books.
What else? I know it's a new toy and has that novelty appeal, but I am so enjoying using it - as well as, but not instead of, paper books, of course!
(PS re. Linda's comment, it's this model I've got).