Which micro SD cards can I use in my OMC?

[Guest Wacky.ddw]

I currently have a ADATA 16GB Micro SDHC Class 4 card wich came with my phone. Costs (19€)

Would a SanDisk microSDHC 32GB Class 4 Card be worth the upgrade (26€), or if you want a faster SD do you have to buy a class10? Wich allmost costs the double or is the difference not that big?

[Guest Fairlight2x]

I bought the Lexar 32GB Class 10 on Amazon's Black Friday sale (£25), that works fine too.