Each channel, R,G,B has a brightness value. 8 bit gives you 256 values, 16 bit gives you 65536 values.
It would depend where your images are going next.
I always keep as much info in my files until the final output, ie print or web. If your computer can cope with dealing with the bigger files, then cant see a reason for not using 16bit. (even if some people claim they cant see the difference)