If you want the flash over the lens you need a bracket. Custom Brackets are wonderful. I've tried Gary's products and they will work in certain situations. Like in a smaller room with light colored walls. The diffuser that comes with the Nikon SB800 works very well for me. So does the flip-it.
Gary's products absorb too much light and force you to use a higher ISO and wider f/stop. If you're shooting a group shot you will have depth of field issues at wider apertures. So to get the f/stop you need you have to move closer to your subject and now you may need a wide angle for the group shot which introduces distortion.
As if all this wasn't enough, I recently tried Gary's products on an SB800 at B&H photo in NY and was appalled at how poorly, in my humble opinion, his products fit on the SB800. Gary's maximum profit approach to have one size fit all really means, in my opinion, that one size doesn't fit very well.
My advice go to a store and try Gary's stuff. If you like it great. If you go to a store with a good return policy you can try it on location.
One great thing about brackets is they give you a place to attach your radio slave for triggering other flash units.
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Nikon D3, Nikon D300, Nikon Lenses 10.5, 14-24, 24-70 2.8, 70-200 VR,
85 1.4 Other brands: Zeiss 50 1.4, Canon G-9 & Underwater housing.
Nikon TC-17E II 1.7x,Three SB800's, Two Quantum 5d-r's, & More.