Exactly. They also have a single window switch as well.
Differences:
dynotune version (which may be same as Zex) has WOT switch built in, and it reads out the actual voltage it's seeing so you KNOW it's set correctly.
Has skip a gear function in case you don't want to spray in first.
"Warms up" instantly, and avoids what John (8yourM5) ws talking about.
The MSD has always worked flawlessly for me, but I always wondered if it would work during the first 10 seconds when it's going through its initialization stage.
The one at dynotune is a metal body as well. Is smaller. Mounts better. Has clearer directions.
And I believe I have no bias. I'm currently running the MSD window switch AND the dual RPM switch from Dynotune.