Thanks all for your valuable inputs.
If you are not aligned with the runway, I don't know if the donut behaves similarly to an ILS G/S but I don't think so.
That's one things that bugs me when I'm told to use it as a guidance as you turn base (with CF as FROM WPT and RWY as TO WPT). I don't know whether it's guiding you along the surface of the '3degree geometrical plane' to the runway like ILS GS (ie not much vertical displacement when you are on base) or is it actually giving you 3 degree descent along your actual circuit flight path(ie continuous 3 degree path to the runway threshold from base).
I guess it's nothing to lose sleep on I was just curious.