I think use of Vsource is more useful in noise simulations. You can directly get input referred noise. I did in this method long back after suggestion from Cadence support and dont know about the new version changes.
my method is to input differential noise source(using vdc(ac=1) and vcvs), use noise analysis to simulate. output noise selects voltage, and input noise is port. after simulation, use results in ADE to check input-referred or output-referred noise, or calculate noise power in a band.
I think use of Vsource is more useful in noise simulations. You can directly get input referred noise. I did in this method long back after suggestion from Cadence support and dont know about the new version changes.