fast and enough space

For Lexar card:
- Capacity 8GB => usable 7,46GiB
- Write speed (supplied card reader): 1.5GB file ~ 11MB / s
- Write speed (built-card reader Acer NB): 1.5GB file ~ 16MB / s
- Read speed (supplied card reader): 1.5GB file ~ 17,5MB / s
- Read speed (built-card reader Acer NB): 1.5GB file ~ 17,5MB / s

For comparison my one year old 10 Kingston 2GB card:
- Write speed (built-card reader Acer NB): 1.5GB file ~ 5.5MB / s
- Read speed (built-card reader Acer NB): 1.5GB file ~ 12,5MB / s

It follows the supplied card reader in the USB stick is not design the fastest (my SanDisk 16GB Countor creates the same USB port ~ 16MB / s write). However, it is useful if you are traveling to the corporate notebook, which does not have a card reader.
Another design flaw of the card reader is easy Captive cap. If no SD card is inserted, this can also be plugged onto the back of the stick but not with card.

Conclusion:
The map is what you want with a few little things that could be improved, see Card Reader. Unfortunately, even the price of capacity and the write speed may be a little high. On the other hand, I've bought the card anyway).