Rowland Preamp - Which model to buy

I can only comment on the Rowland pieces I own/owned. (I have not owned or heard the Capri2 or Coherence II.) I had the JR Continuum S2 integrated (which I believe has a built-in "pre" fashioned after the Capri2). I currently run the JR Corus+PSU. The Continuum S2 integrated is worth its price point. It delivers the JR sound admirably. However, if you can swing the Corus+PSU you will not be disappointed. It is superlative on every front I can think of. I have heard the Corus, without the PSU, driven by the Rowland 625S2 amp. It sounded clean, what I would describe as neutral, with a very low noise floor. My Corus+PSU is driven by JR 925s monos. It delivers a deeper more holistic soundstage than the Corus/625S2. It also presents the instruments on the soundstage with greater detail/resolution. The noise floor is even lower with the Corus+PSU. I haven't heard a preamp that provides as great an increase in resolution and depth with as low a noise floor without driving the sound towards brightness or brittleness. "Best bang for the buck"--I actually think the Corus+PSU qualifies, but I readily admit it is a lot of bucks. But, it could well be the most transformative dollars you spend in your system.