I'm hearing a little bit of wavering in Wakana's voice, but nothing too major. I hope this doesn't become a regular occurrence though, I don't mind it in lives as, well, it's live, but recordings should be able to deal with that a lot better.
So far I'm not sure what to make of it. I think I'll start to like it a bit more after a few listens like I did with Alleluia, that's the kind of vibe it's giving me. It's got more potential than Believe (not hard) but that really depends on how the full version sounds, since Believe actually got worse as the full version showed off all the atrocious transitions that weren't as obvious in the TV-size. On the other hand, it's obviously trying to be similar to Believe in an attempt to link the two together as the series are, probably something that was requested by the director more than anything.
Heavenly Blue and Believe were both terrible but then they brought In Every Nothing and Lapis, which were both great, so I'm mostly just waiting for the b-sides. I've always thought their tie-in songs post-Seventh Heaven have been weaker than their album tracks/b-sides anyway, it's nothing new.