Got back last night. Had a blast and keen to get out there again. Walk in wasn't too bad, in snow from round hill with good coverage along the ridge. Start was crapola though as we had to walk an extra few km due to a fallen tree halfway along Doherty's road.
On Buller itself, the conditions were pretty good. Lots of snow around and well packed on the final climb to the summit. Most of the rock around main st and the gullies was iced over.
Didn't get close enough to the waterfall area to have a good look but it looked alright from the ridge.
Some pics that give a rough idea of the conditions: