Interesting thought. Not aging, not losing your health or mental ability, I would consider it. Do I really want to be around and seeing the ongoing deaths of my descendants though? Does it mean I am invincible, not able to be harmed or killed? Hmm, interesting. I could take risks that others would not dare, which could advance so much perhaps. Would my immortality benefit mankind, and me? What if I couldn't make any difference at all? Would I get bored with it all? Would it feel like a nightmare that I could never awake from?
Truly, I think I just want to live long enough to be satisfied that I have experienced enough of the world around me and seen that my children are raising their own children satisfactorily.