I seem to have avoided the problems with Lion, by virtue of not having gotten around to buying it for a while.  Procrastination has its uses.

The battery problems (not those that Charlie Miller found, which seem to have been rather overblown by the media) appear to be getting worse: the battery is still taking forever to charge, and the charge doesn’t last as long. The power management “decisions,” on the part of the computer, are inconsistent.  Often, even when the computer is actually plugged into the mains, the mouse will be shut down, presumably to save power.  On the other hand, sometimes when the computer goes (or is put) to sleep, the USB power is obviously still running, and the mouse sitting there glowing like a nightlight.

Something is not right between Apple and Twitter.  Looking at Twitter via the Web interface (using Safari) is fine–as long as you are only looking at a few screenfuls of postings.  if you go back several hours, and are dealing with a Web page with hundreds of postings, the Mac becomes almost unusable.  The same size of page viewed with an old netbook running XP and Firefox is slow, but definitely works.