Wow yes I see this:
https://www.oneworld.com/airport-lounges?location=SYD
Never had a problem at SYD F, it gets busy, but never difficult to get seats. Been a while since I used SYD C international lounge, and it was a bit tatty, and it is getting refurbished AFAIK so may have limited space whilst that is underway. I'd stick to QF F myself, but if I could only get into QF C usually, I'd give The House a go. See Ausbt review here
https://www.ausbt.com.au/house-renov...s-room-to-grow