[gTen]

The card may start out the same if it is a Class 2 but once it begins to fragment it becomes worse and worse...the Class 2 indicates that once fully fragmented the min guaranteed speed is 2mb/sec, a class 4 would be 4mb/sec and class 6 would be 6mb/sec...

so can a Class 2 end up similar to a class 4 or 6, yes..but its a risk that you take....

to find out how well your card performs, do a speed test of like 100x for both small sizes and large sizes..by then you should be able to tell what effect fragmentation has on the card.