Yeah, absolutely. Astarion explicitly describes it as a "cycle of power and terror" and refusing the ritual means he was able to break that cycle. He still has the symptoms of being a vampire spawn, but he's managed to escape the 'power-is-all' mindset of true vampirism. Just, the whole conversation afterwards, bolding for emphasis:
"It feels ridiculous to still be thinking about Cazador. He's gone, I'm here - I won. But I still keep reliving everything that happened. Playing it over and over in my mind."
"In the ritual chamber, you were someone else. Someone unrecognisable."
"You’re not wrong. Cazador left his mark on me in more ways than one - for a moment, I wanted to be just like him. I came so close to losing everything back there. To losing myself. Back at the ritual, all I could see was the power on offer and the safety it promised. I was so blinded by it. Just as Cazador was. But you saw something in me - someone else I could be. Someone who could break through the cycle of power and terror that started centuries ago. You saved me back there. I may not have appreciated it at the time, but I do now. Thank you."
"You saved yourself, I just gave you a push."
"You did more than that. You believed in me - believed I was enough just the way I am. When I look at my future, anything and everything feels possible now. And I get to share it with you, as a partner. An equal. You saved me from myself and let me walk a new path where I can be free. Truly, honestly free. This is a gift, you know. Thank you - I won’t forget it."
Even unromanced, the scene is identical, it just omits the, 'as a partner, an equal' line. His genuine happiness, relief, and gratitude, Neil's incredible performance, it's just the emotional climax to his entire story. Then the epilogue, where he's genuinely content in himself - he's still a vampire spawn, he still needs blood, can't see his reflection, can't see sunlight, but he's free to be himself for the first time in centuries. In refusing the ritual, he gains himself.
How anyone can think Ascension is the right choice after that is beyond me, honestly.