I've been on both of those skis and the Facet Regulators. I would also add the Line Blends to that list.
IMO, you are choosing soft, rockered skis. Because every ski has a ton of rocker, you shouldn't look at a 164. You should size up since the part of the ski actually touching the snow will be shorter on a rockered ski vs a cambered ski. based on your height and weight, I would put you at about 169-172cm area for lengths.
all the options besides blends are 90 underfoot, so I am guessing that you are trying to get something skinnier.
If you don't like the idea of blends, then out of the ON3P,s J's, and Facets, I have to say that I liked the flex profile of the Facets the most. Very smooth and stable for buttering, and they are insanely lightweight. I enjoyed skiing these the most out of the others. The only downside is that they could have some different graphics to look at, but you are looking at next years gear anyway.
Riding the J's, I felt like they were honestly too soft to actually ski some terrain. I also think they were too narrow in the tip and tail to perform as well as the Facets outside of the park (thinking some fresh snow or trees). Amazing ski in the park, but the narrow shovel on the tip and tail made it harder to smear butters and hold nose manuals. Super quick on rails and really light though.
Mag's are probably the best all mountain performer out of them, but thats only because they are so stiff. The only reason people can flex and butter like they do on these skis is the rocker profile. For some people, this is ideal, but for someone like me, who also enjoys slow speed butters, it was more of an effort to butter. They are also noticeably heavier than the other options. When I jumped on a pair at hood, I was impressed with how much fun they can be at moderate speeds, but I felt like they were too swervy. On jumps, I didn't feel like I could lay down a nice landing without feeling like I could accidentally swerve out. It was personally very annoying, but it was designed by Magnus, so it makes sense that it is so easy to swerve. Definitely not my style since I find it annoying when you are just trying to stomp a trick and the skis are trying to swerve to switch on their own.
The blends are just straight noodles. Really only good for the park and some moderate speed pow, but they overflex too easily which can lead to washouts depending on what you are doing.
Overall, I put my vote in for the Facets. I liked their flex profile the most since it felt the least restricting for every type of skiing. I also liked the tails and noses since it felt sooo good to butter on them.