All of the information in that link has been discussed before. The problem with trying to equate a propio degree to a U.S. unaccredited state authorized degree is that one can come from an accredited school (propio degree) and the other cannot (U.S unaccredited degree). It's also worth mentioning that Spaniards are very much aware of the importance of institutional accreditation, and a propio degree from an unaccredited school will be noticed and scrutinized, and in many cases rejected. All propio degree programs are not created equal nor are they viewed as such by the general public. As for the recommendation of the writer, she is free to give it, but it would be wise to only concern oneself with what an official NACES evaluation states (if an evaluation is important to the degree seeker) and what your employer or potential employer may think.