I think TextMate 2 integrates better with OS X UX guidelines, it has a really beautiful interface, better finder integration and it has more Xcode-ish tools, like source control panels. Sublime Text does a pretty good job on integration, for a cross-platform software: it's interface's components don't feel alien in the system, it has support for overlay scrollbars, etc. In fact I think ST2/3 integrates better with OS X than with any other platform.
However, regarding editing capabilities I wouldn't stick with anything else than Sublime. It has better keybinding settings, it's way more extensible.
TextMate 2 is definitely an OS X app - along with other editors like Chocolat and Espresso - but if you're comfortable with Sublime, stick with it, it does a good job in order to not feel alien compared to the others.