Personally, I like both seiyuu but if I had to choose between the two, I'd go with Sakura's Tsubasa seiyuu. I like how it sounds more gentle and it just sounds more natural to me. You have to admit that Tange-san makes Sakura sound so unnaturally squeaky and high-pitched, even for a ten year old Japanese girl. Sakura's Tsubasa seiyuu just feels more natural to me somehow. Also, correct me if I'm wrong, but didn't Tange-san retire? So, even if Tsubasa wasn't an AU to CCS, I don't think they would've been able to use Tange-san as Sakura, anyway.