RBrooner

The file OS is FAT32 which only supports 32 GB partitions (Microsoft limit I believe). Guessing that if you put a larger one in and format it it will only be 32 GB. (Please note I haven't tried it, just making a guess.)

I have the PX-560 and 2 Roland Cm-30 speakers. The build in speakers are 8w + 8w (stereo). A single CM-30 is 30w. The speaker in the CM-30 is larger than the ones in the PX-560 so in my opinion it overall sounds better than the internal speakers (e.g., covers more range and volume.) I do think the internal speakers would be enough for very small gigs where the room might not be too loud.

I always turn off the internal speakers. I use two Roland CM-30s and and a cheap subwoofer - Rockville APM10C. (A better woofer would have a mid/hi pass filter outs to the other amps - but it works fine for home use.) When I take the keyboard out and about I typically only use 1 CM-30 for a monitor (connected from the headphone out on the keyboard.) and connect the regular outs to the venue sound system. People typically wind up with a complaint about the CM-30 not having a "monitor" out - but you can use its headphone out for that if needed. (It has outs for connected to another CM-30 to get Stereo sound).