Did they also lower the fluence level since you were still tan? I have been treated with the Lightsheer at 100ms two years ago on the center of my chest and had better results than at 30 ms. Regrowth seemed to be much less than at the shorter pulse widths.
I would say that a lower fluence level and having some suntan left probably affected your results more than the pulse width.
Why don’t they use the longer pulse width? Because it takes longer to treat an area at that pulse width. The repetition rate is not quite as fast as at 30 ms.
I am a big fan of the Lightsheer. But if your skin is that dark you would have been better off with the Aurora or maybe a Nd:YAG laser like the Sciton or Coolglide. I tried the Sciton recently on my beard and was quite impressed with it. Very little post treatment redness and that was gone in a few hours. A week later clumps of hair fell out of my beard while shaving. I will have a follow up treatment in the end of May.
I prefer the Aurora over the Lightsheer for dark skin. But if the tan has faded and the skin is light, I say crank the Lightsheer up to 50J and blast away. I had a test spot on my beard with the Lightsheer and it smelled like my beard was on fire. It was painful but tolerable even without EMLA. There was quite a bit of redness and the sunburn feeling so we decided to go with the Sciton. That was the first time we used the Lightsheer on coarse hair that was previously untouched by laser and the hairs exploded out of the follicles like they did with the Apogee. ZZZZZZZZZAP! That’s a great sound to hear when having laser hair removal.
Your tan will fade eventually and you can go back to 30 ms if you want but I would try both settings on lighter skin and compare the results.