Whitecap.
On the XA 30.5 vocals (and tonality in general) were much more natural, with better instrument placement and a more 3-dimensional soundstage. This was true whether I was listening to Kanye West or Sonny Rollins. The 250.5 had a bit of harshness that really stood out on the Thiels (as would be expected, and as I was warned by Pass), but had very slightly better bass control. That room was a bit of a mess on the bass though (old wood floors floating over a crawl space in a weirdly shaped dining/living room combo), so perhaps I couldn't hear as much improvement in that area as there actually was. Also, just for clarity, I've never heard the XA60.5s (or.8s). Ohh, and I did have both Pass amps at the same time, so my decision was based on A/Bing.