Photog get together

[DanL]

Fred,
I'm confused too.  Ike says "a diffuser is included", but I wonder if he is referring to the deflector used for the optical fiber to pick up flash to signal a separate strobe (eg the Inon optic fiber slave activation).
Go to digitaldiver.net and post the question to Ike on the housings forum.  He will answer.  Or call them - they are really good on tech support.
The deciding factor for me, if you do want my two cents, is the likelihood of wanting a wide angle lens in the future.  The Canon housing seems not to allow any lens add-ons because lens port is not round.  If you are sure you don't want to add a lens in the ffuture, get the Canon housing.