Tamiya X-11 is not bad for a metallic acrylic, but like most metallic acrylics it suffers from a larger metallic grain size than its enamel or lacquer counterparts. What this means is that while it's acceptable, you don't really get that deep, lustrous metallic sheen that enamels and lacquers provide.
I haven't tried them but I've read good things about Gunze's "Mr Metal" range. I believe they are a lacquer based product.