Yeah i tried/owned Sundara, XS, Ananda, Arya Stealth all. It was surprising to hear that their hierarchy was accurate. You can hear the jump. But also they all were going for different type of sound despite having very similar frequency response.
Arya and Ananda goes for that speaker like soundstage 60 degree in front. XS gives you surround kind of soundstage which works somewhat better for games and movies. Sundara is pretty much standard headphone in this front. XS goes for v shape sound, Ananda goes for romantic texture and mid, Arya goes for energetic fast sound, Sundara also aims for energetic fast sharp sound. XS sound somewhat loose, Ananda sound light and soft, Arya sound bold.
I'm very curious about HE1000 Stealth right now. Hopefully i will be able to get one. Slowly going up in Hifiman ladder
Arya Stealth kinda feels like combination of Sundara and Ananda to me from my memory. I hope HE1000 Stealth is like combination of XS and Arya Stealth.