Grey Whistlers don’t have any particular ‘look-at-me’ traits but they are delightful little birds. I think of them as having a rather pleasant personality (perhaps a somewhat anthromomorphic description) as they quietly hunt for insects without any apparent aggressiveness towards other insect hunters. They have a sweet, almost tentative call that sounds to me like it is not quite complete. We see them on their own or in pairs and sometimes in mixed foraging groups.
There are two races of Grey Whistler (Pachycephala simplex). We have race peninsulae here and we have observed such a huge variation in the extent and depth of the lemon-yellow underparts that we have occasionally wondered if we also have the nominate race.
Allen
Barbara
Wild Wings & Swampy Things 
Interesting post as always and terrific photos
Sometimes the modest and unassuming birds are the most interesting.