OK

Still camera photography ...

(1) For the data you supplied, are we talking about jpeg or RAW formatted images? 

(2) If jpeg, does the camera change the jpeg compression when a faster card is available?  It is possible that with a faster card, the camera will save larger files. 

(3) Camera autofocus time is another factor ... that would be constant no mater what the memory card speed ... in fact, that could dominate the performance numbers ... and might obscure the timing improvement granted by a faster memory device. 

--Martin