My answer was tongue in cheek, but if you don't want to listen carefully, the weight is as dependable as any other spec.
Amplifier specs, does they matter?
For solid state designs, the manufacturers boast about their signal to noise ratios, total harmonic distortions, slew rates, frequency responses, and many others. Meanwhile, the makers of the tube amps praise the liquidity and musicality of their designs. Obviously, amplifiers with tubes don't measure nearly as well as solid state amps. So, do any of these specifications really matter?