SD cards write speed : SanDIsk

As a canon user I have a collection of Compact Flash cards that should last me a while.
But with the SD slot in the 5DIII I am looking at the SanDisk SD cards for the second slot and wondering about the write speed:

ExtremePro 95MB/s
Extreme 45MB/s
Ultra 30MB/s


What speed does the 5DIII write:

I have always been a fan of using smaller MB cards and a lot of them.
The reason is if a card get corrupt or loose one I have not lost the entire day.
I change about every 500. ( I shoot 3000+ at a wedding).
I plan on shooting and saving the images to both cards as an added security.

I have always used SanDisk in my Canons and really not thinking of changing unless better quality exists.

Thank you

http://www.petapixel.com/2012/06/24/dont-use-sd-cards-with-your-canon-5d-mark-iii-if-you-care-about-speed/

And Bryan saying the same thing:
http://www.the-digital-picture.com/News/News-Post.aspx?News=2595

And a table:
http://www.robgalbraith.com/bins/camera_wb_multi_page.asp?cid=6007-12452

David....Thanks for the links. That is an impressive drop off in performance going from CF (up to 80 MB/s) to SD cards (<20 MB/s).

I was also pleased to see how similar Galbraiths results were to our tests on the 7D.