The matrix does have ceramic particles in the alloy, to stiffen it. It'll still polish up. The welds will not have the ceramic and the weld process causes the ceramics to run away from the weld. So, it'll polish, the welds may look slightly different.
As for how it'd look, well there's nothing wrong with a polished bike but as has been said very generic.
How about polishing a section middle of down/seat/top tube where decals would go.