I just set up my new Prime over the weekend. Right out of the box - wow!
To my ears in my system, it is a substantial upgrade over my former Classic 1. I found the Classic 1 lacking in upper bass/lower treble, making it sound very lean. The Prime is dead neutral and dead quiet. This is real bargain for what it is. Once it fully burns in I'll compare it to my reference - a heavily modded Teres. I'm pretty sure the Prime will be quieter, but not sure that it will match it for detail retrieval, bass weight and body. We'll see.