It's no secret that I'm a bit of a REGA fanboy. As I sit here typing this I'm listening to Andrew Jackson Jihad through an all REGA system (PC, DAC-R, Brio-R and RS1 bookshelves). It's completely overkill for a desktop sound system, but it's where I spend all my time, so it's worth it.
Part of what I love about REGA is the sound, I just seem to enjoy the music I'm listening to through a REGA system a bit more. The other part of what I love is the simplicity, the no frills approach to building components. It speaks to a type of minimalist approach that seems to sit at the far side of a scale in Hi-Fi (the other side being gold plated OTT valve amps, which I like for other reasons).
But I digress and think it would be easiest for Roy Gandy to explain it himself. Watch how REGA got start and how it's unique approach was developed here: https://www.youtube.com/watch?v=7EfvHl8-88U