is the rega brio better than the rega mira 3

I LOVE the Brio. I think it is THE deal in hifi. Yes, in my estimation, it is more musical than the Mira.

Thanks for that. I wonder perhaps whether it is the Rega sound which I am struggling with. It just doesn't seem to engage me as much as I thought it would.

I used both. The brio runs out of steam before Mira 3 will, you get the sense that things are being pushed foward with a loss of composure when you crank it. At moderate levels the Brio is nicely musical. In a nutshell it is "good for the price" performance, similar to NAD. That said the Mira 3 is more detailed and 3D- as you noticed. The Mira holds together better at higher levels- it plays cleaner and still has the 'ol Rega "timing", bass is not very weighty, but you will hear every note clearly. Brio bass is a little softer. Brio design is based on an old radio circuit and I found it to be sensitive to RFI in my environment. I would keep the Mira or consider a true step up.