Recommendations to others considering Test IO:
You do need to spend some time creating documentation of the "features" of your application so the testers will know what and how to test. This can be done over time, however. As you run more tests, it becomes apparent what gaps there may be in your descriptions, so you can improve on that. Review collected by and hosted on G2.com.
What problems is Test IO solving and how is that benefiting you?
I sleep better knowing the site is extensively QA'ed each week -- we have a test scheduled after each weekly release. Test.IO has helped us efficiently discover, prioritize, and fix problems that impacted our users. Our on-staff QA is freed up to spend more time collaborating with our dev team on new features, while Test.IO can do the majority of regression testing (outside of automated testing.) Review collected by and hosted on G2.com.