The look good, and they have great reviews, I think Pipeman uses the SK402 or 403 and has for a while and he has great grows.
Pipeman reminds me of a guy I knew that built and sold sites for bow & arrows, he would put on shows and prove with it he could 6 out of 6 arrows in a beer can at some distance I dont remember but it was impressive. What most folks didnt know is that guy do that with or without the site.
So I am thinking Pipeman could have pretty good grows under a flash light. lol