Why are most comments referring to having used this in the past tense? I was under the impression that it was still the best image viewer in town, on Windows at least
The built-in viewer in windows is fine. I can't really think of a feature that it doesn't have that I need. Could you say why irfanview gets your vote?
It's about speed mostly. And I got used to the shortcuts, ctrl+r to resize, 'i' to check image metadata. I don't really use any of the editing features (I use Paint.NET for edits).
In theory I don't need a dedicated image viewer but I like IrfanView so much that I even paid for it so I can have it on company's laptop.