My oldest has been going to Orpheus for her piano and music lessons since 2012. In 2014, I got my youngest to go as well.
I especially like Orpheus philosophy that learning a music instrument needs to be backed by a strong theory. When I was growing up, my piano teacher taught me to play piano, but never taught me music theory. I feel I'm missing some music foundation. I think my kids will have a richer musical life knowing a decent amount of music theory. I like the fact that we spend approximately equal amount of time on theory (in a group) and on instrument lesson (individually).
Another aspect I like about Orpheus is the opportunities to collaborate amongst students. Orpheus' annual Friendship Concert where multiple kids collaborate to perform a duet or triplet is just about my favorite event of the year.