Thank you, i appreciate the detailed responce. I’m going to order the card now. 
It would be interesting to see what the benchmark results are for the Class-4 and compare it to the Class-2.
I find it strange though that the SanDisk website has no reference to the newer Class-4. Mostly because it makes it difficult to verify whether its a legimate card - other than ask on these forums. I guess there must be a lag between releasing newer/revised products and updating the website.
