I just stayed here for two nights at the weekend, with my family, and had a great experience.
As a Diamond-just-bumped-back-to-Platinum, they had trouble applying my Suite award upgrade certificates, to the two-adjoining-rooms booking. I resigned myself to "no Suite for you!".
After a small "complaint" about the adjoining rooms, the General Manager upgraded us immediately to a Diplomatic Suite, the "Menzies Suite".
Entry area, guest toilet, kitchenette with separate butler's entrance, dining room, living room, master bedroom, very large walk-in-wardrobe, large bathroom with jacuzzi, two balconies - one overlooking the fountain and circular entrance driveway, the other overlooking the grounds to the croquet club.
Awesome. AUD$1025/night list price!
Of course, Ambassador Club privileges, which my daughters loved, for breakfast/daytime snacks/evening canapés.
It's an old-ish, "heritage" hotel, with lots of history regarding the Parliament/seat of Federal Government.