As a relative newcomer to WordPress (couple of months) I rushed in and upgraded to 2.5, although quite happy with 2.3.
Sidebars and widgets: The old drag and drop was fine but getting used to the new one. My only personal problem is, using four or five sidebars, I keep forgetting to click ‘show’, but I’m sure I’ll get used to it.
Categories: Not sure I’ll get used to the location. Too much scrolling and, at the moment, I invariably forget and have to go back and edit later. Altogether far too much scrolling involved in posting now.
There are obviously bugs with the images – alignment doesn’t work, inserting image works intermittently and half the time left with a blank pop-up and no image in the post. Seems to work better with a new upload as opposed to a library image. Tedious having to code the images, though, when this happens. Sure this will get ironed out as so many seem to be suffering similar problems.
So, with bugs, no perceptible decrease in load times, slightly unhandy layout and posts taking longer to actually write and publish, my initial reaction was to downgrade or change, but maybe I’ll give it a little time to see if things improve.