Ultra compact with AE lock?
Exactly, that's what I find so useful with the AE lock on the Ixus. I can sample the light anywhere and lock the exposure without there being an object to focus on. The normal focus lock doesn't do the trick. I often find the AE lock faster and more useful than e.g. adjusting ev + -. I find that first measuring light and locking exposure, then finding focus and locking, then possibly reframing again before taking the shot, can often give very good results. (This is of course even more useful if there's a live histogram).