Got a new Creek OBH-22 passive preamp today from audioadvisor.com, a demo deal for $75 off. I've been testing it out for a couple of hours now and it's... different. My first impression is that it's either much less forgiving than the Act III or it's just plain not as good. It's definitely a lot warmer and analog sounding, which improves listenability, but this tends to hide some of the raw clarity and crisp tight bass. Some well produced stuff still sounds really good though (rift, brothers in arms), so I think it is just perhaps less forgiving, because how much could it really be effecting the sound? I think maybe the act III does a lot more than I thought to the raw signal, without it some recordings don't sound as good as they used to. Everything sounds a little warmer and less digital, for better or worse and bass, although present, doesn't seem as tight.
Physically it's really small, the faceplate is only about 4"x2", but it seems to work as advertised and it doesn't even need power to work input 1 which is cool. So the acurus cd player is now going coax digital (aq vdm-5) to the LinkIII DAC, analog (MIT AVT1) to the Creek, analog (MIT AVT1) to the McCormack, then to the speakers (MIT AVT1 biwire).
Theoretically I should be getting a straight, clean signal from the DAC to the amp, and it definitely sounds different; it's either a lot warmer, not as fast and tight, or both.