To answer your question, the shadow is very noticeable and will likely bother you. I have a 65 g rr with the black plastic center brace and hated the shadow. I ended up going with 2 x 175w halides to avoid the problem.
VAlgae, is showing you a replaced center brace. Some people cut the brace and replace it with clear acrylic. It works and I considered doing it but was too chicken.
