Katy Manning did an interview for Big Finish podcast, and they asked about her return as Jo Grant on the Sarah Jane Adventures. She had a lot of nice things to say about working with Elizabeth Sladen and the rest of the cast, including Matt Smith.
Link Here:
http://www.bigfinish.com/news/Katy-Manning-Podcast Here's what she said about Matt:
"He really is one of the most creative young actors I have ever ever worked with. He really is so creative. And he is the Doctor. And not only that, not only is he this incredible creative actor, who is perfectly cast, he is also the most charming young man. I mean, he is an absolute delight."
She also mentions being on the new Tardis set, as well as getting to hold the new sonic screwdriver, and Liz Sladen's sonic lipstick.