I think that's one of the best treecats I've seen in a while, and that uniform looks pretty great, too. I do see a few problems with it, though (If you don't want to hear about it, just ignore this next part).
The upper left sleeve is 100% accurate for a Petty Officer 1st Class Environmental Technician, but that's an Enlisted rank. Cuff rings, shoulder boards, collar insignia, the Space Warfare Pin, and dress swords are only part of Officers' uniforms. Additionally, the white beret is only worn by an officer in command of a starship, and the only collar insignia arranged like what is shown here is that of a Fleet Admiral - much too high-ranked to command a single ship. Finally, the buttons are only worn on the Dress and Mess Dress uniforms; if this is a Dress uniform, there should be no sword, and if it is Mess Dress, the shoulder boards are replaced with epaulettes. And for both Mess and Mess Dress uniforms, the award ribbons are replaced with their corrosponding medals. Finally, the sword amnd sword belt aren't regulation, and the collar insignia don't exactly match those of any RMN rank.
Individually, each portion is very accurate; the problem is that parts of several different uniforms are mixed and matched.