Klipsch Cornwalls vs. JBL L110 speakers with McIntosh MC2205

I am considering a vintage 1978 pair of Klipsch Cornwalls or a 1979 pair of JBL L110 speakers- both will have updated crossovers (and woofers for the JBL). I would like your input as I will not have the luxury of a side by side comparison. As well, I will be running either pair with a McIntosh MC2205 (rated 200W RMS per channel @ 8 ohms. Should I be concerned about the amp just idling rather than using more of its' power due to the efficiency of the Cornwalls? Or, is it an advantage to have that much headroom? Thank you for your input on both the speaker selection and the amplifier question.