A:Answer Hi Ryan,
I have a 43" Samsung attached to this mount which is probably a bit too big for the mount. It is a great mount though, and seamless to move. It swivels very easily and probably rotates sideways about 75 degrees, not a full 90. That may be because my TV is on the bigger side of the mount range (I believe it is 19-42"). Having that said, if your tv is 40", it will probably be similar to mine and will not rotate the full 90.
You will have to check on the compatibility of the mount with Vizio as I am not sure.
Thanks
JD