System Shock is definately correct, I hate that damn stuck note...
One thing to note with OmniMidi is that it loads your SoundFonts in order based on how you have them listed- you will want to make sure you have 1mgm listed above synthusr to ensure it loads fist.
For a bit of a different midi "taste" I personally like to load up the Roland SC-88 soundfont before the other two, and it seems to work for the most part:
https://musical-artifacts.com/artifacts/538