Depends on the circuit. No competent design should be device critical in that sense. Opamps are assumed to have infinite input Z. In practice they have not (bjt types) but it would be spectacularly bad design if gain were "opamp input impedance dependant". The ratio of applied input voltage to input current gives the figure... and it's tiny (I) making the resistance huge, even for a device like a 741. If you built a circuit using 20meg resistors then (apart from other issues) you might notice the design really was device dependant, and had a different gain if you swapped a 741 for TL071 for example, but for audio it doesn't come into it with any normal design. DC servos are one example where low input current (and consequently high Z) is of utmost importance.
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