Sublime isn't open source and free.
Speaking as someone who used Textpad from 1995 until when I discovered SublimeText last year, I love the functionality and keyboard shortcuts that have been built into it. For example, the developer appears to have lifted CTRL+F2 / F2 for bookmarks directly from Textpad, and I'm very happy they did.
I for one am happy for the developer to move at his own pace. It is very solid for my purposes, now using the Ubuntu version having switched from Windows.