Markers are a nice element to annotate different sections of the song.
You might already have mentioned them: Tempo markers are supported too.
Each beat can have a text attached.
Chord names can be useful to indicate how to play a song. Chord diagrams are also shown if available.
Beat vibrators and note vibratos are both available.
From piano pianissimo to forte fortissimo, they are all there.
Especially bass guitar players will like this feature.
This annotation is shown if you need to increase the note volume from silent to normal when playing it.
If this annotation is placed on a note, you don't stop the string after the beat ends.
A feature you won't miss: Palm Mute markers.
String bendings can be rendered by alphaTab as well.
A lot of electrical guitars come with whammy bars. alphaTab shows whammy bar effects.
Tremolo Pickings are rendered too.
Brush Strokes are shown as arrows on the tablature stave.
There are several types of slides alphaTab can render.
Trill effects are rendered on the tablature stave and on an effect line.
Pick strokes indicate how to play the strings.
Tuplets are used to divide beats into equal subdivisions.
Finger indicators can be used to highlight which fingers should be used to play respective note on the instrument.
Triplet feels are used to indicate that a pair of particular notes are played with a different as they are indicated by the annotations.