Besides the Uniball Signo and the Pilot Hi-Tec-C, the Pentel Slicci line of gels is one of the most popular options available on the market, and for good reason. Sliccis are available in a range of tip sizes and colors, and the needle point tip is incredibly sturdy. What's more, the writing performance is excellent. Though I have seen the 'Metallic' ink options, I hadn't tried one until this sample was sent over by Pentel.
Being metallic, the writing sample was difficult to photograph, and the perceived ink color changes quite a bit depending on the angle and light with which it is viewed. These writing samples were taken today in a Minnesota sunset - your results may vary.
The bottom line? I can see a lot of people liking the Metallic Sliccis. If you haven't tried a Slicci, make a point to find give them shot. The barrel is a bit thin, but they are worth taking for a spin either way. You may have difficulty finding these in the big box stores, but you can find them online at JetPens.com.