The main differences (besides possibility of larger banks in an Emax-2) are:
- the Emax-1 uses compressed samples in 8 bits while the Emax-2 uses linear 16 bit samples. When loading an Emax-1 bank into the Emax-2, the Emax-2 sampler automatically converts the samples in the bank (takes a few seconds...). The difference in sample format is the main reason why most other samplers don't support Emax-1 banks.
- the Emax-1 deals differently with stereo than the Emax-2. In some cases, after loading an Emax-1 bank into the Emax-2, you may have to correct the stereo voice/panning settings because the sound may only be heard on one channel (depending on the panning settings and dual voice settings on the Emax-1). In practice that's the only potential bit of work that you may have to do.
FYI: as mentioned, EMXP can convert Emax-1 banks. One of the conversions supported is the same conversion to Emax-2 format as is being done by the Emax-2 sampler itself when loading Emax-1 banks. So if you convert them in this way and e.g burn the converted banks on an Emax-2 formatted cdrom, all samplers that support Emax-2 banks can read your banks...