Wife and I just stayed here last week. Below are my thoughts;
Our last night we stayed at the MH and booked a family suite on points. Upon arrival, we were upgraded to a Panoramic Suite.
Got to be honest, after a few nights at the Conrad and WA I was a bit underwhelmed staying here. It is obvious that the hotel is older and there was a noticeable difference in the staff. I guess the MH is your typical 4* Hilton property.
Although the room was recently refurbished, it was not done to the high standard of the Conrad of WA. It looked almost cheap. Yes, the views were amazing of the city, but that was about it. Everything else was a bit meh.
Breakfast was nice and had a decent selection, the pool area was not all that, and rather small.
To summarize between the 3 properties (Conrad, WA & MH);
If money is not an issue for you, or you have a free certificate then without question stay at the WA. You will not be disappointed.
The second choice would be the Conrad considering the comparable price point against the MH both for cash and points.