Pass Labs versus Jeff Rowland, Audio Research

As I am considering replacing my trusty pair of Jeff Rowland 7M monoblocks, feeding a pair of MagnePan IIIAs, I am looking at both the current Jeff Rowland lineup, as well as at the latest incarnation of the Pass Labs X series, dubbed the X.5 series, and some Audio Research models.

In the Rowland lineup I am considering the 501 monoblocks, or the 302 stereo amp, while I have already determined first hand that the smaller 201 monoblocks do not drive the MagnePan IIIA pair adequately.

In the Pass Labs lineup I will consider the X-250.5 (already released), the X-350.5 (just out of engineering), and the upcoming X-600.5.

From Audio Research I already discarded the otherwise extremely lovely VT100 as just slightly underpowered for the Maggies, but will consider the VT200 stereo, the new VSM220 monoblocks, as well as the VTM200 monoblocks.

The rest of my system consists of EAD T1000 CD transport and EAD DSP7000 Mk3 (these likely to be replaced by Esoteric X-01, and an Audio Research LS2B.
I most listen to classical, and within it more to solos and small ensambles than to large orchestra.

I'd value all opinions! In particular any comments concerning the relative merits of the newest Pass amps vs the other brands would be very appreciated.
According to Pass and to those dealers that have already the new X.5 models, these new boxes have a more refined and detailed sound than the old X models, and a fuller fleshed-out midrange. But, how do they truly stack up to Rowland and Audio Research?