I'm all in favor of the new Luminous Mysteries for the simple reason that I've often prayed the Joyful Mysteries, then the Sorrowful Mysteries and wondered why there's nothing in between the finding of Jesus in the temple and the agony in the garden.
I see only one downside: John XXIII Publications has an absolutely horrendous version of the new stations of the cross with "adaptations" psalms that replace masculine references to God with phrases like "Holy One" and "Mighty One." I'm sure we'll see some other clap-trap out there disguised as legit publications around the new mysteries.