I thought about it for 10 seconds but I only have one unit and I'd rather keep it fully legit atm, plus the memory cards aren't good value for money.
I'd probably do it if there was a straight forward way to play backups on it, and a huge library of such backups existed.
My PSP already has a ton of old stuff on it anyway...I have 2 different CFWs on separate dual SD adaptors.