I’ve been using it since 2004 - it is my go-to editor for any kind of source code. I have even expanded and customised the code highlighting files to achieve better experience.

UltraEdit is, without a doubt, fantastic and does everything it says it does and more - and very well. It is unfortunately marred on the usability side by that stupid ribbon. A professional tool should have the same controls always in the same place and not reformat its toolbars based on window size. I spend far too much time looking for stuff that used to be there. Also, the loss of vertical screen real estate by this monstrosity does not really go well with the fact the all screens today are wide and not tall. I wish more developers would not follow MS's stupid design ideas. In addition: some of the buttons and other window elements are not really well sized for a high resolution display - that is the main point for improvement I see (or rather - don't see :-)