And by that title, I Mean that the drive current to the gate of the MOSFET when the BJT is on differs from the drive current for when it is off .I know that it would cause a difference between Toff and Ton but is there any other reason why it might be a bad choice? Let's assume you have an NPN transistor that can handle a much higher peak collector current than your PNP in the push-pull driver, would you still configure the BJTs so that they both have the same collector current even though your configuration is only bottlenecked by the PNP transistor? I would also want to know if asymmetrical driving is can be used for buck converters.

symmetrical drive:

Asymmetrical drive: R5 <<R6 (NPN can handle more current)