A question on amp matching

I'm looking for a new stereo amp.  Among all the other specs, how important is gain in addition to power output at a rated speaker impedance?

I just auditioned an amp at the low end of recommended power for my speakers, but it also seemed to have lower rated gain than other amps I've used.  It was disappointing for output level, bass extension, and dynamics.  So should I be looking for both greater power rating and higher gain?

Obviously I'm looking for general guidelines since I omitted specific details of the components in question.