*MESS cannot write to disc images in DSK format; only MFI (MESS floppy image) and MFM (HxCFloppyEmulator floppy image) are supported for writing.
*Some demo tricks may be broken in MESS, e.g. overscan pictures are horizontally misaligned (shifted to the right).
*Loading extension ROMs is also not supposedly supported, but it is difficult to figure out the correct commandline parameters. The documentation is pretty useless here.
*CPC+/GX4000 emulation still has some obvious graphics glitches.
*The emulated CPC464 has the AMSDOS ROM loaded which is a problem with early 464-only programs that rely on the 464's larger free memory.