I will try make it possible to switch my program back and forth between using JOGL and Java2D so that I can compare performance. In the worst case scenario, I'll just switch back to Java2D.
If you are disappointed with the performance, maybe you will try to find what is wrong rather than switching back to Java2D.
However, Slick is more than an OpenGL binding, it might be useful in order to avoid reinventing the wheel, it contains some nice features (fonts, tiles, gradients, SVG...) and a quite good documentation (a wiki translated into my mother tongue, thanks
). It could be interesting to have an equivalent of Slick that would rely on JOGL for those who want absolutely to use JOGL instead of LWJGL and use such a good library.