Lately, it seems that the weight (huge) my keychain (loaded) eventually influence decision and weaken the quality of the connection. I therefore avoids leaving the keychain for its weight when I plug in front of a desktop.
Otherwise, RAS. When I change it, I probably take the same USB Version 3.
The size of 16GB is more than enough when we next laptop HD (I do music and photography which involves large amounts of data).