The recommendation of greater than 300 watts is totally false.
I've heard the Discoveries with 100 solid state watts sound fantastic. You could probably get away with 70-80 if the amp is just right.
That's not to say that more watts aren't better, that usually is the case with solid state amps. But you will be MORE THAN FINE with your ML 23.5's.
The Discovery's are a fantastic speaker. Enjoy them.
Regards,
George