Climbed Brewer's Buttress on Castle Mountain today.
The route is in excellent mid-summer condition. There is water available in the normal spot (in the gully just before traversing to the hut) and it looks like this could last for a little while due to some snow patchs in the gully above. There are a few small snow patchs along the summit ridge, but they are all avoidable. There is also some snow in the bottom of the descent gully, but if you stick to the standard descent and make use of the rappel stations, the snow is not an issue.
Have fun!
Jeremy Mackenzie
ACMG/IFMGA Mountain Guide
jeremymackenzie@hotmail.com