For me, same thing: no other editor gives me the decent UI of a GUI-based editor, but with the speed of vim when working with large text files (e.g. 10MB+).

I will often use sed or other CLI tools to parse through giant files (1GB+), but sublime only takes a short bit to load in a pretty hefty file, or a do regex search across entire projects with multiple-GB of files, and it works natively on Mac and Windows, so even when I'm forced to work on something on my Windows 10 laptop, I can be productive.

Well worth whatever I paid for it 4 years ago.