I have a J68, which is the same basic design in 9mm. In general, I like the simplicity of the basic design. They've even managed to create a good trigger, especially for a bullpup. Unfortunately, it's not very reliable. It's good enough to be a range toy, but that's about it.
It's both the easiest rifle ever to field strip and the most annoying. All you have to do (at least on the J68) is pull a little lever near the buttplate and push the top out of the bottom. Then the works is just kinda sitting in the bottom half. What makes it annoying is that the two halves don't separate without tools. They just hinge at the front, which is really awkward.
It's really fun to shoot when it's working well. But it's also a bit of a project gun that you have to tinker with.
Yes, that thing right in front of the magwell is the mag release.