I finally got out to check out Oregon's first variable speed zone, at the intersection of U.S. 26 and Oregon 47 at Staley's Junction/Manning (this is in Washington County, northwest of Banks).
No, the signs are not the same as WSDOTs. Oregon uses a black on white sign for the speed, mounted within what is otherwise a standard Oregon speed sign. Having driven through the zone yesterday both during the day (around 6:00 PM) and again at night (around 10:30 PM) I have to say that the signs are HORRIBLE. They cannot be read at a decent distance, and the white background is just annoying. WSDOT's signs are so much more clear and legible.
(I didn't have a problem with overall traffic speed, but the only time I'm in Seattle is on a weekend...where it seems all of the traffic is backed up between JBLM and downtown Tacoma.)
I noticed another peculiarity with the U.S. 26 VMS zone - westbound, there is just a "Variable Speed Zone Ahead" sign. Eastbound there is a yellow "Speed Zone Ahead" warning sign (yes, in a diamond, and yes it said "Speed Zone Ahead", not the new style picture sign!) followed by a "Variable Speed Zone Ahead" sign. And another, the variable speed zone is not even a mile long; in fact there's only one variable speed sign in each direction, approaching Highway 47. Once you're past 47, you are back to the standard speed signs. I can't honestly see how that will accomplish anything - I thought the variable speed zone would have at least covered a couple miles to the east towards the east junction of 47 towards Banks.