I use SublimeText on Linux and haven't got any first-hand experience of TextMate. I have seen coworkers use it and as far as I can tell, the main difference between them is SublimeText is much faster. It loads in under 1 second on an old PC and working with files feels instantaneous. It's also available cross platform so you can get the same experience on any computer. Well worth installing the trial then shelling out for the licence IMO.