Now that I've experienced the first transcendence too, I can say that it took me under a day to get back to A30 so it's pretty fast, I don't have the feeling that I have to re-grind everything all over again.
But with the current mechanics, I don't think there's any chance for us to get to the higher T levels just yet. It took me 1 day to get from A0-A30 again and it's gonna take another day to get from A30 to A33, with the later levels being even further apart. I don't think I'll be able to get to T2 anytime soon (meaning A60). The gold/xp diff is just too high right now (and I'm pretty far ahead in the corrupted nexus + talisman, I have at least elites for all the pets + min 60 corruption on all of them, etc.).
But overall I think the transcendence coupled with auto-ascension is a good system to have!