A year ago I tried to use a micro SD card to expand memory and was less than satisfied. Micro cards are not built as robust as regular SD cards. I had three and they all corrupted now and then. The Mac seems to treat the card like a USB device, and there were sleep and wake issues along with mounting and unmounting quirks. Speed for photos or video was not an issue, although slow, but if your use case is a lot of read/writes, the micro SD cards don't seem to work well in that environment.
If you mean regular SD cards, they are much better, but you need like 96 MB/s rated ones for really big RAW photos. 4-5MB images are no big deal, however.
Oh, by the way, mini adapters similar to the nifty drive are widely available in the US. For some laptops, the housing needs to be shaved a bit to fit.