I use Sublime Text 3 and is very satisfied with the speed. It is extremely fast.
It starts so fast. I used to use (x)emacs.
However, I loaded a 800MB file and wanted to search in it. That was almost useless.
Sublime Text was quite sluggish. Note that I am only using 6GB of 16GB.
I do understand my file is HUGE and to extent I am surprised it did not crash.
So the slowness is to be expected but you always hope for the best.
I wonder if huge file performance is something that is important to you.