Ive been keeping them for years now.
The main reason they sulk is that the dont like change, Once they are old enough to sex, set them up in their adult/permanent enclosure, dont change things around once they are settled and you will never have a problem.
With all honesty, in my opinion, the sulking thing is an old argument, its dates back to wild caught animals.
Multi gen captive bred animals seem to sulk a lot less (if at all).
Also, all mine get tong fed ( woodies and pinkies) and hand fed fruit (banana apple pear ect). This gets them used to interacting with you and they do tame up very well. In saying that, like all reptiles they can have bad days, and get moodie every now and then, when this happens leave them be for the day.
The next day give them a feed (by tongs) and they seem to chirp up again.
In my opinion, they are one of the best lizards you can keep.
They are an Australian icon and Ive had nothing but joy keeping mine.