SkiEssentials calls them “very similar skis” and Blistergear mentioned the Menace 98 in the Black Ops 98 review as they have “similar shape and weight” and the measured flex patterns were almost identical with the Black Ops 98 being a hair(0-5%) stiffer and the menace being heavier.
I think one of the biggest differences that people have felt between these skis lies in mount recommendations with the BO 98 having a single line 4.75cm back from center and the Menace 98 has 2 lines, with one for freestyle at 1.75cm back from center and the all mountain line back at 7.75cm back. Typical ski demos will probably put you on the 4.75cm rec line on the BO 98 and 7.75cm back on the Menace 98(unless the person demoing mentions freestyle or laps in the Park). People on here debate .5cm or 1cm differences in binding mounts so you can imagine a 3cm difference on similar skis. If you mounted both at the 5cm back range for example, their similarities would start to grow.
BO 98 has a slight bit more taper tip/tail (but very little compared to most freestyle skis near that width) compared to the Menace so the BO is a hair more surfy in soft snow and the menace a hair more “locked in” on turns on harder snow. Slightly longer turning radius and higher weight of the Menace make for slightly better crud performance while the lower swing weight on the BO makes them easier to spin in the air.
All these differences aren’t huge and if you like one you’d probably like the other.(Again when comparing them to each other in similar mount positions). Both are fun, playful skis that are blast all over the mountain.
Also, either ski should be “sized up” as they are twin tips with tip/tail rocker and fairly forgiving flex patterns. Skier weight range on either the 182 BO or 181cm Menace would be in the 150-190lbs range and those over 200lbs should really be on the 187cm menace or 192 BO especially if the skier is aggressive or skis in more open areas.
Both great skis and I could happily live with either. I prefer the top sheets of the Black Ops but I also like the prices on “old stock” Slicer skis.