The latest issue of Stereophile has a review of the Rhea in which the author takes quite a bit of time comparing it to the Io. I think it was written by Paul Bolin, check it out.
Aesthetix Rhea vs. Io Signature
Having read most of the posts re: the Aesthetix Io (both with and w/o signature and dual power supply upgrades), I think I understand its excellence, yet have not auditioned it. However, I'd like to keep things fairly simple from a heat/maintenance/no.of boxes/cost standpoint. Thus, my interest in the Rhea. Would those of you who have experience with the Rhea vs. the Io comment as to the distinctions. The concern I have is how much body, weight and richness of soundstage is sacrificed vs. the Io (let's assume with single power supply, signature version).