One reason why I like PSPad is that I can use it for three main tasks - editing text files, diffing text files and hex-editing files. Notepad++ seems to have a hex editor plugin, do you know if it's any good?

It seems fine as a basic hex editor, but I haven't used it that much. Not sure what would happen if you gave it a large file. I've been happy with HxD as a dedicated hex editor that works well with large files.