I agree with a lot of the things in this article, but wow, I could not possibly disagree with this quote more. Ctrl+[ is WAY more uncomfortable than using the Escape key.
Granted, I have many years of vim usage that have made hitting Escape a habit, and that probably plays a big part in it, but Ctrl+[ is downright painful for me (and yes, I sat and tried it for a while in vim to see what it would be like).
I can get from the home row to Escape and back with very little effort, though I understand that is not the case for many people. Perhaps it is due to the fact that I use my ring finger to hit Escape rather than my pinky (which would be a lot more work, I think).