Ok done more research if you can get hold of HDAdvance 3.0 then get it, otherwise you can download HDLoader 0.8b for free (google it) and burn it. HDAdvance is better as it allows Dual layer DVD's to be written to the HD unlike HDLoader afaik.
The usbxtreme is less compatible with games as the 2 above and the loading times will still be slow because of the fact its usb.