A thorough study with equivalent functions, I opted for this HP50g and I confess not to be disappointed, far from it.
I could find almost all my duties and my programs; the processor being newer, calculations and treatments are faster.
I added a 2GB SD card and it is certain that for the transfer of text files in particular, is 1000 times faster than the cable from the HP48GX (and this also saves batteries).
I highly recommend this machine and for lovers HP48GX, you need a little adjustment period because the keys and functions are not willing to the same places but HP was smart to keep the same interfaces so as not to confuse .