Any written music score is only a rough guide to what any decent musician will play. Mechanically reproduced music, as a midi played from a typical score is generally going to be too "mechanical" to be called "musical." It might approximate what you'd get from a player piano or an amusement park calliope.

A midi exported from any score producing program generally will import into another scoring program that has midi in/out capability, and the score from the midi will (almost always) look very much like the original score from which the midi was made. One thing that won't "come back" is due to the simple fact that when a midi is created it includes all the notes played in the order they happen, with no such thing as "repeats" or different endings on repeated phrases, so all of those will disappear if you try to bring back the original score from a midi made from it.

A midi made by recording from an instrument, imported into a score, will look like a bunch of maggots got loose on the paper and were chased around by a flock of hungry small birds with dirty feet - hence the common name "maggoty score."

A very few composers have attempted to write precisely what the instruments should play with results that are very much like the "imported midi player" results. Nobody's ever been able to read enough of one to want to play those compositions so far as I've heard, but the music world is full of many very strange people so one can't be too sure.

This particular quirk has little to do with which program you choose, since all programs that create scores and import/export as midi will produce almost identical results. Editing features in the program might affect how easy it is to clean up an imported midi that's got lots of worms in it, but so few people actually use all such features (there's always an easier, if slower way) that they're not documented at all in most pre-sales descriptions.

Among lower priced and shareware/freeware programs, documentation is likely to be very sparse so it may be difficult to tell what a given program can do. For those where you can find something about what they do, you will need to decide what's important and what you can get along without.

A few things you may want to watch for:

1. Not all scoring programs are "midi capable" so that you can export the scored piece to a midi file or import a midi file to make a score.

2. Relatively few scoring programs produce tab output, and some that claim to don't do a very good job.

3. There are significant differences in note-time range, although most will handle full notes down to at least 64th notes. Better ones will let you include 128th notes and some go to 256th notes.

4. Many of the cheaper/simplest programs will let you type in repeats, DS, DC, multiple endings for repeats, and such so that they show in the score, but can't actually play them in the playback or include them in the midi.

5. The better programs will generally allow at least 8, and some permit 16 staves per system. A couple I've seen only allowed 4, so you probably should check this if you might need more than 4.

Beyond that, about all one can say is "Good Luck."

John