First, does a converter offer the connectivity now and into the future that you will need? Most studios try to get several years of service from their converters, so being able to Use it now and adapt for the future is important.
Second, how well does the converter work with today's and tomorrow's computers? Windows as well as mac? Pro tools as well as nuendo, wavelab, cakewalk, reaper, etc. Third, if you can't connect to your computer, you can't connect to your customer.
Let's take a fair and only slightly biased look at how these three converters connect.