Having had the Zestro now a week, I can begin to make some preliminary comments on my impressions. When A/B'd with the EAR 834p Deluxe, a pretty clear node must go to the Zestro, as the 834p is a bit less resolving, not as deep in soundstage presentation, and warm to a point of being slightly nebulous, partic. in low frequencies. Recently, the game got interesting, as I now have a Herron VTPH-2, borrowed from a colleague, and have to say that here, things are very competitive. The Herron has great detail and solid presence of the stage. Source placement is spot-on, though it may not throw quite as 'wide' a stage as the Zestro. Transients are also a forte with the Herron, with low frequencies being particularly solid. Where the Zestro may have a slight edge is its seeming ability to create a more visceral experience - timbral accuracy, partic. with percussion, is very impressive. The soundstage is also not only slightly wider, but deeper, more separation of sources. The Zestro is also slightly warmer than the Herron, and doesn't pack quite the punch in amplitude, though cranking it up a notch or two to compensate doesn't introduce more noise - very black backgrounds. I could likely be happy with either the Herron or the Zestro, but the listening continues...
Just my 2 cents worth at the moment - thought I'd share ~