Hi sugarplumsss,
Genos contains all the voices and effects of Tyros4/5 (and most other previous Tyros and PSR-S models). So you can use MIDI files that were originally programmed for the Tyros4 on the Genos without any changes. Nevertheless, in a direct comparison with the T4, there could be slight differences in the playback of the files on the Genos, mainly because the Genos has a different type of tone generator and better digital/analog converters (32-bit) on the main outputs.
If you have MIDI files revoiced with T4 Custom Voices, you would need to save your Custom Voice Library on the T4 to a folder on a USB stick (using LIBRARY SAVE). Then you connect the stick to the computer and import the .UVI Library file from the relevant folder into the Expansion Manager (YEM) with "Import Pack". This automatically creates a new pack in the YEM from the .UVN/UVD Custom Voice files (which must also be in the folder where the .UVI file is).
Note: If other packs have already been imported into the YEM, the pack with LSB 000 must first be moved to another free LSB number and then the pack with the Tyros4 Custom Voices must be moved to LSB 000. After the Pack Installation has been carried out (via USB stick or WiFi), MIDI files that have been revoiced with T4 Custom Voices can also be played on the Genos without any changes.
By the way, the only real downside I think the Genos has over the Tyros5 is that the Genos touch screen is much dimmer than the T5 display and non-tilting. Under unfavorable conditions (direct sunlight or very bright stage lights from an unfavorable angle), it can happen that the Genos touch screen can no longer be read/operated. (The solution could possibly be a sunshield that is attached over the Genos touch sceen.)
Best regards,
Chris