I used to use MuseScore a lot, usually for piano arrangements, but occasionally for chamber and choral works. I’ve even contributed code in the past, and it’s great to see how far the software has come. I could make a decent looking score in MuseScore 2.0 — that is, with enough manual effort. But eventually, the manual edits got tedious, and the scores I was writing got more complex. While I didn’t need other software, I wanted it because it would improve my workflow. I basically outgrew MuseScore, and so I moved to Dorico.
To start, Dorico offers a lot of nice notational and engraving niceties that would often have to be made manually in other software. In MuseScore, I would have to constantly make horizontal and vertical spacing adjustments (especially with lyrics) to avoid collisions and to make the music look good. I’d also need to change slur and beam angles (especially around grace notes) and manually hide rests, especially in multi-voice contexts. I’d have to constantly check note values and beams against the prevailing meter, and check courtesy accidentals against the notes in the surrounding measures. These are all relatively mechanical adjustments that I believe the software should do for me, as Dorico does — it’s actually kind of hard to get weird-looking notation in Dorico. (Some of these were addressed in recent versions of MuseScore, but not all.)
Scoring is an iterative process, and revisions are a necessary and expected part of that. However, they are generally much more painful to execute in MuseScore than with Dorico. Want to adjust meters or rhythms? Get ready to manually fix a bunch of rests and tied notes. (And I hope you don’t have any tuplets.) Decide you want notes in one voice instead of two? First you must convert the voices to the same rhythm, then move the notes to voice 1, then delete the rests that appear in voice 2. Want to edit a bit of music for Flute 2? Don’t forget to make a corresponding change to the condensed staff and part, and any cues it might be in. Want to change the way a playing technique text looks, like making it italic? You’ll need to change it in every instance in every instrument in the score and every part. Each of these operations takes several times longer in MuseScore than in Dorico. Plugins can help bridge the gap, but it’s annoying to have to run them.
It can be difficult to achieve certain kinds of notation in MuseScore. (Daniel lists quite a few in the first reply on this thread.) Some of these things can be done in a hacky way, such as ossias — you add an extra staff to an instrument, hide it throughout the score, and reveal it where necessary. (It also only works on whole measures.) Another example would be a tuplet spanning two measures — use a double-length measure with a fake barline. (Don’t forget to add a corrective bar number change!) Other notations such as forked unison stems are practically impossible. I mean, I suppose you can add any kind of notation you want by inserting text and graphics (indeed, this is what a user might fallback to with Dorico), but the time and effort to get it to look adequate can be substantial. In contrast, native support for that notation makes entering it fast and effective, and it makes you wonder why you ever bothered with the alternative.
Editing in MuseScore is not without its perils — it’s almost too easy to make certain kinds of edits, and making them inadvertently can lead to a lot of headache later on. You can drag elements around to modify their visible and/or logical position: drag notes up and down to move their pitch, drag dynamics left and right to move their timing and precise placement, etc. Sometimes this can result in accidentally applying spurious overrides to these elements. For example, dragging a note right increases leading for the entire segment (spacing column). This can make it hard to get consistent spacing throughout the score, especially if such edits are made unintentionally. One would be wise to use keyboard commands to make these edits instead, as they have more predictable results. But don’t accidentally press up or down, as this changes the pitch of the notes. And pressing the opposite key does not put it back, as it might result in a different pitch spelling. Dorico adds a bit more friction to make logical changes to the notation, and ensures visual-only adjustments can only be done in Engrave mode.
Playback in MuseScore has always been very finicky. In order to play VSTs, I’d have to run MuseScore through JACK and a VST host. I’m glad that it supports VSTs natively now, but it does not appear to have any kind of expression mapping capability yet. MuseSounds is an interesting development, and the demos sound very good, but it doesn’t seem to be very customizable. (Even NotePerformer offers some influence over the interpretation by way of CC overrides.) Actually, right now, the user cannot exert much influence at all over MuseScore’s playback. (The piano roll in MuseScore 2 used to be horribly buggy, then it was massively improved in version 3, but now it’s gone until they rework it for version 4.) You’d need to export the MIDI to a DAW and make the necessary adjustments to timings, keyswitches, and CCs there. On the other hand, Dorico turns the notation into suitable and tweakable instructions for your VSTs to make a good mockup without needing a separate DAW.
All of this is to say, MuseScore is fantastic for what it is: free, entry-level software. You can do a lot with it, but it might be painful — for both the user and the player. Dorico can do so much more, with a lot less pain.