Yup, the FSB while a highly reliable backup sight if the optic dies, blocks a decent sized portion of one's view. I prefer high quality flip-ups for that reason.
Printable View
I've tried running front and rear flip ups and the Troys were the closest I found that felt solid enough. If I'm running a variable powered optic I run a flip up rear. If it's RDS I much prefer a fixed FSB and a fixed rear. I've gone back to the Larue fixed rear as it's built like a brick shithouse. Next I'll try the DD fixed rear as people I trust highly recommend them.