A quick word about MIDI
MIDI has come a long way in 30 years and there are some really good MIDI sampled sounds. But music that sounds right coming out of your computer still might disappoint you on the band stand.
Balance, tone color, voicing, and voice leading are all critically important to the quality of a chart and, unless you have a ton of time on your hands to tweak every element of the MIDI output from your score, MIDI will lull you into a false sense of security on these elements.
Balance, color, and voicing can best be learned through study, experimentation, and experience. Music that you really like to listen to is likely spot on, so grab a score and try to figure out why it sounds good. Conversely, if something sounds wonky, that is an opportunity to learn from somebody else's mistake.
Voice leading, to a certain extent, can be corrected with your ears and eyes and on your own - pick up your instrument and play the parts you have written. If a part doesn't flow, look for a different solution. I'll write more about this later - a lot more.
Generally, I only use the MIDI output as a note check.