I guess it's only fair to put in my two cents. Much like CLyrics, I wasn't very in tune with their new voices. But I will say that I was able to adjust to them pretty quickly after being able to watch "Get Ready for School" several times on On Demand. Here's my opinions on each characters' voice:
Molly: It's decent. I'm SO glad Brianna Gentilella is able to continue to do Molly's singing voice because she was great.
Gil: I'm glad that they kept his voice from season 2.
Goby: Oy. Let me put it this way. It could be much worse than what it is. I don't love it but it's not bad enough in it's own right to call it incredibly awful. I'll miss you, Jelani Imani.
Deema: I like it. Kudos to Grace Kaufman (I think I spelled her name wrong) for TRYING to sound like Angelina Wahler. Her singing voice isn't half bad either.
Oona: When I first first heard it, I thought it was the worst. But after watching "Get Ready for School" and "Police Cop-etition", I think it sorta matches. I loved Reyna Shaksan, but I give credit to her replacement for being halfway decent.
Nonny: I really like his new voice. It's really cute and I think it sort of matches the tone of his character. Don't get me wrong. I enjoyed Eamon Pirruccello, but his replacement makes a better Nonny.