Hi rly
They very much do. The Americans are still using it (in the Olympic Training Center). And so are the russians and Chinease as far as i know.
I know that Dr Bill Sands, and Jenny McNeil recently (like 2007) did some more research on the effect of Vibration and flexibility of gymnasts, but i am not sure if they have released any new study findings.
Sorry of taking so long to reply.