On my Rubio there's a big difference. Augustine Regals are nowhere near as even as the PEPESR across the strings. The Regal trebles are bright whereas the PEPESR trebles have a rich warmth. Also, I've had some intonation issues with Augustine strings in the past.
About two weeks ago I put a set of Augustine Regal strings on my Alhambra 4P (I had one set in my string box and I've been trying to pare down my inventory of random strings). They started out VERY rich and resonant, but after about a week, they have become very uneven from bass to treble. The trebles just lost their punch. I have tried Imperials in the past, too, and they always seemed unexceptional. I know many on this forum swear by Augustine strings and their Imperial trebles and I apologize if I have hurt anyone's feelings, but this has been my experience.
"Art is not something which you can take or leave. It is a necessity of human life" -- Oscar Wilde
2012 German Vazquez Rubio Estudio - Spruce
1979 Sakurai Kohno No. 10 - Cedar
2006 Alhambra 4P - Spruce