They are very different. The JJ has a lot of side cut resulting in a short turn radius (14 m) and is softer in the tips and tails, with taper at the tips and tails. The crj is straighter with around a 30 m turn radius and has a more consistent flex pattern. Also if I remember correctly the JJ has more abrupt rocker, while the crj's rocker is more gradual.
The JJ is a good example of one class of powder skis, along with the S7- sharp side cut so people coming from quick groomer skis feel more comfortable, and also more maneuverable for tree skiing; and steep tip rocker with soft tips so that the skis plane up quickly in powder, better for beginner powder skiers and areas with light snow. However these features make both the S7 and JJ less stable in crud and at speed.
Definitely demo the crj's before buying, if you can. A lot of people don't like the long turn radius, especially if they are coming off of quicker groomer or park skis. Also the crj is pretty damp, and kind of strange feeling.