I received the Uni-Ball Jetstream 0.5mm Basic Series as a sample from JetPens (along with a Uni-Ball Jetstream F*Series that I will review next week), and if there is one thing that Uni-Ball has completely under control it is the design and functionality of the Jetstream line. With this particular model, the 0.5mm tip size is introduced, and being the fan of micro-tip pens that I am, I love it.
The extra fine line it lays down is right up my alley, and the crisp, clean design of the barrel makes it a joy to write with. You would think with such a fine ballpoint tip there would be a lot of drag and friction when writing, but I can lightly move the pen across the page and the line is just as good as if I was using my regular writing pressure.
If you are not crazy about the extra fine line, then the Jetstream Sport 0.7mm is a great option. But if you like the combination of a ballpoint and an extra fine and clean line, then the Uni-Ball Jetstream 0.5mm would be a great pickup.
Here are more details from JetPens: