10-15 minutes is a long time to wait for results, especially when you're asking for feedback. The freeform text box isn't helpful because it lists a bunch of things I should tell it but not _how_ I should tell it.
You can fix both by offering samples, better guidance and structured but unobtrusive input where it matters.
edit... now that I think about the wait time, is there any AI behind it at all? I haven't seen an application of AI that takes this long ever, but have seen ones that push onto mechanical turk (or equivalent) and hope for the best.
