It seems I'm in a minority, which is fair enough, but there is one comment that transitions aren't Ben's strong point. To clarify this point, it's often only after the transition that I realise that it is a different character who is talking. Also, when Ben uses different intonations for different characters, I think that sometimes he's going at such a pace that the voicing slips, as he doesn't keep up with himself.
I've heard many worse readers, and I think that with just a bit more effort or coaching, Ben could be really good.