The first thing I would say, is how different Passive's can sound from each other. I had a chance to compare 4 Passive Pre's over a weekend, which might not have been long enough, but two were frankly poor, muddy, lacking detail, dynamics and base. I had a DIY built clone of the Music First Audio Baby reference and an actual Baby reference. Both were excellent in comparison. In fact, what one is led to expect from a Passive, quite neutral, transparent, with no hint of colouration to my ears. The actual baby reference was a little better.
On the basis of this test, I believe the MFA Baby reference is hard to beat compared with many active Pre's. Like Kernelbob, I think it clearly bettered the ARC Ref 3.
What am I using now, the Modwright 36.5? I just prefer it to a Passive, greater dynamics and a more engaging, enjoyable, musical, for want of a better word, sound. Still if you get a chance of auditioning an MFA Baby Reference in your system, give it a try. Before anyone else says it, I agree, it is quite expensive, so try and find a second hand one.