i also recently bought 1 of these to play with my dads old sunpak flash with a 37v sync. works great! have to shoot with my M lenses though because it needs to have the pre flash disabled on the on-board flash (which i believe can only be done by using a manual lens)
but here is a test shot with the sunpak off to the right with a bit of old plastic from a milk bottle in front of it as a bit of a diffuser, and the onboard covered with a bit of paper (still manages to trigger the optical trigger fine though)