I like my UA-5 because it offers phantom, pre, A/D, and the ability to run a matrix 'on-the-fly' by utilizing the rca inputs in conjunction with the mic inputs. I actually prefer the sound of my AD-20 (with my AT mics; I haven't run the AD-20 with my C4's yet), but that may change if I get my UA-5 busman modded. I personally prefer the convenience of the 'all-in-one' box rather than using a phantom>AD-20 setup.