Well, I use QWERTY, and I've hit 124 wpm before (on a cheap silicon-dome one, no less! I've bought a mechanical, and once I get used to the feel I'll go beyond that). It's definitely possible to get 160+ wpm on QWERTY; just check out Das Keyboards' Ultimate Typing Championship (
https://www.youtube…).
I know DVORAK is more efficient than QWERTY, but I'm not switching because every business uses QWERTY keyboards, and I don't want to switch modes when I'm at home and at work. However, if you're only working at home, you might give it a shot.
Take care,
Stephen