First off big fan of Sublime and use it every day.
The only pet peeve for me is find and replace performance using regex. I find if I have a file with upwards of 50000 characters and I do a simple newline replace or text substitution on the file, Sublime hangs and does not respond, eventually completes the operation or crashes completely. I've tried the same operations in ultraedit et al and it works in the milliseconds with no problems.
Is this a known issue, or am I doing something silly?