Regarding the subject of active XOs, it is almost impossible to find one that is built without op amps. Bryston is the only company that comes to mind that produced HP and LP versions with discrete Class A circuitry, and I do not recall if these are still in current production. In any case they are not cheap, and if you need more than just a single XO point (two way system), the costs mount up fast.
This stance is a quick way to discard active XO’s when in fact they could be beneficial to a passive solution - even with opamps and A/D to D/A conversion being introduced in the signal chain.
What’s the bigger picture; do the comparison and forget for a while the drawbacks mentioned to hinder the fuller realization of an active XO, if they’d even be that relevant compared to the negatives of a passive config., and then see. My take with an XP-series Xilica XO is that it trumps excellent passive XO’s in the three set-ups I’ve heard so far - quite easily. The sound in all cases went from slightly diffuse/smeared and soft to more clear, refined, transparent and dynamic going from passive to active.