Melville is OK, no BBQ's and toilets a good walk away.
Point Walter was OK

and may suit most so there isn’t a long drive, but disadvantages those at Mandurah in that situation.
Peli Point has all those facilities, but can get crowded out real fast
Mandurah, lots of space, plenty of BBQ room, toilets and such, no problem. so for me Mandurah.