I've had quite a few stays at a Sebel branded property here in Australia. The front desk signed me up to the GHA program, and started giving me the Gold benefits (bottled water and free internet) straight away.
I usually book through the Qantas website, to get the bonus miles, and they still give me the GHA benefits.
The kicker is that this week the GHA website price is $50 less that the Qantas rate!
The GHA website doesn't show the number of stays or nights, so I'm not sure how you tell when you get to higher "status" with this program.
But compared to SPG, the free internet just for joining the program makes it all worthwhile for me.