Help me choose an active crossover

I need an extremely high quality 3-way crossover for a high resolution system (see virtual system). The midrange/tweeter unit will be crossed over at 600Hz, and will use a Cary CAD-211AE amplifier. The woofer will be bandpassed between 80-600Hz, and will be powered by a solid state amp. Everything below 80Hz will be sent to stereo subs.

I have narrowed down my selection to two models in the Marchand catalog - the XM44, and the XM126.

The XM44 is a solid state crossover, which can be ordered with any frequency slope from 6dB/oct - 48dB/oct. You can specify optional daughter boards, including notch filters, baffle step compensation, delay sections, and Linkwitz transform. It is relatively affordable - specified for my needs it would cost $1350. Link is here: http://www.marchandelec.com/xm44.html

The XM126 is a valve based crossover, only available at a maximum 24dB/oct slope (although 1st, 2nd, and 3rd order slopes are available). The website does not list any optional daughter boards. My understanding is that the XM126 does not use any op-amps, and all the circuitry is discrete. Which probably accounts for its whopper of an asking price - $4700 (with attenuator, balanced option, and 3 way). Link is here: http://www.marchandelec.com/xm126.html

As far as I can see, the extra money for the XM126 buys you a better volume control (i.e. a stepped attenuator instead of a potentiometer), and it buys you discrete circuitry instead of op-amps.

Now, I do not have a philosophical objection to op-amps per se. I would not exclude a product simply because it uses op-amps, as long as the result is what I want - clean, dynamic, with a low noise floor and extremely high resolution. I do not care so much about the superior tonality of valves, because I have already achieved the tone I want elsewhere in the system.

Obviously I would prefer to spend less, but I am prepared to save for a better crossover if need be. I also wonder whether I should consider a crossover from Nelson Pass or Bryston instead of the Marchand. Your opinions?