They are nice medium size parrot - large enough to be an easy to work with companion animal yet small enough to still sit on your shoulder comfortably and easily house indoors in a cage that doesn't take up half the living room. I also really like that they are sexually dimorphic (visually sexable) and the females are as colorful as the males but in a slightly different way. So for a pet, it really doesn't matter if you get a male or female as both are very pretty. The calls can be somewhat loud but are not screeching and nowhere near as loud as most Conures /Macaws /Cockatoos /Amazons. The calls also have an interesting pattern to most of them.
Down side: Hard to come by. I find them far more desirable than an Indian Ring Neck (I've had IRN, Plum Headed and Mustache for the Asian Parakeets) and arguably are not harder to breed, yet very few people seem to have any paired up while IRN are extremely common. Plum Heads would be my second choice of this group and even those are far, far less common that IRN's. Very few mutations out there for Mustache's as well - at least in the US, but then I generally prefer normals anyway.