I bought the Big Flip-It (with diffuser), rather than the Jumbo. As Joe says in his FAQ:
"Should I get the Big or Jumbo size reflector?
"The Jumbo size was created in response to a demand for the largest reflector that would reasonably fit on a flash. It is a style option; the lighting from the Big and Jumbo are the same." -
http://dembflashproducts.com/faq/
I'm wondering if the advice changes with the SB-900, and it's wider coverage. I need to do some experimenting to look for light spill off the edges of my "big" reflector, to see if I need to upgrade to the Jumbo.
(I reluctantly upgraded - I wanted a second flash, and with the SB-900 now going for less than the price gouging going on for the SB-800, a second SB-800 was out of the question. Grrrr... Well, I my SB-800 is now set in remote mode, and I never have to go through the hellatious menus ever again)
I did have some weird light patterns in some recent flash photographs I took:
http://www.i-do-photography.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=3135&g2_serialNumber=2
I thought this was from the pattern of the diffuser material used in the Demb Diffuser, but it turned out to be the tops of the chrome chair frames. I took off the diffuser, and bounced off of the walls, and this eliminated the reflactions from the chair backs.
http://www.i-do-photography.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=3138&g2_serialNumber=2
(Yeah, I know, could use some levels adjustment - for illustrative purposes only)
All the best,
--
'Highlights next to shadows to create detail, depth, dimension and added color saturation.' - David Ziser