Just got my Stealthbar 280mm - fits me perfectly with my RE harness(size S). My waist is 75-77cm. Lengthwise the plastic spreader bar itself(between harness straps attach points) is same size as Mystic Clickerbar 4.0 surf size M. The "stealth wings"(flaps) are a bit on the longer/wider side for size S RE harness, but still fit in nevertheless. The bar is lighter and I have more locked in feeling, seems this combination can not ride up at all!
Yet to test it on water. I will check the option of adding a hook, should I ever want to go back to it. Will post some pictures later if anybody interested.
I wanted to add low friction ring, but after disassembling the bar I am not sure I will be able to make knots on rope again as these are tight and the excess rope is cut off. I will first order replacement rope kit and then try it.
PS. Found this: https://www.mysticboarding.com/howto
tutorial on Mystic web site, was linked on the bar label
Here is a photo how it looks, really clean package.