I just bought a sunpak 383 and am using it straight on the camera's hot shoe and am loving it. The manual adjustments take very little time to get used to. The swivel head is the best - no need for an omnibounce.
Anyway, I found that shutter speed upwards of 320 is too fast for the flash and half the image is dark, actually completely black. I use both flash and camera in Manual. Is there any way around this?