Allow me, to add just some facts.
DL depth of 17.5", weight of 18lbs. Dual fans
XRack depth of 11.3", weight of 14.4lbs Fanless
Both 3 rack space height.
Both essentially specially purposed computers that are susceptible to solar gamma ray or emi corruption and potential show stopper, not much unlike any modern-era automobile we drive, smart device arse warmer we communicate on, or heart pace-maker that perhaps allows some of us to keep on doing what we do best.