I only play kddk so I will talk about that. This is more of a general consensus instead of my personal views.
Pros: (ST = singletap ALT = full alternate)
This is all assuming you are using 4 fingers to play.
ST/ALT - Single color patterns can be done with both hands for better stability/accuracy and comfort.
ST/ALT - Spinners can be done with ease alternating dkdkdkd across 4 fingers. (v c z x v c z x v c z x for example)
ST/ALT - 1/6 combos are generally easier with two hands. ddkkddkkddkk 1/6 being the only exception, much easier on ddkk style using the same technique as spinners.
ST - Finishers won't ruin your rhythm/flow because you keep rhythm on 1 hand.
ALT - Stamina on high BPM won't be a huge issue compared to ST.
ST - Accuracy is generally easier because you aren't focusing on alternating each note. (This probably won't count after playing ALT for a long time though)
Cons:
Still assuming you are using 4 fingers.
ST - Stamina will be your downfall at higher BPM. Going into the higher 200's while using your left/right hand for the majority rhythm will hurt and require practice.
ST - Offbeat patterns like doubles and quads can be annoying because you will start patterns/maintain rhythm on your opposite hand sometimes.
ALT - Finishers will usually destroy your constant alternating note flow/rhythm unless the finisher has a break after it. But more dense patterns with finishers will be a pain.
Pros: (ST = singletap ALT = full alternate)
This is all assuming you are using 4 fingers to play.
ST/ALT - Single color patterns can be done with both hands for better stability/accuracy and comfort.
ST/ALT - Spinners can be done with ease alternating dkdkdkd across 4 fingers. (v c z x v c z x v c z x for example)
ST/ALT - 1/6 combos are generally easier with two hands. ddkkddkkddkk 1/6 being the only exception, much easier on ddkk style using the same technique as spinners.
ST - Finishers won't ruin your rhythm/flow because you keep rhythm on 1 hand.
ALT - Stamina on high BPM won't be a huge issue compared to ST.
ST - Accuracy is generally easier because you aren't focusing on alternating each note. (This probably won't count after playing ALT for a long time though)
Cons:
Still assuming you are using 4 fingers.
ST - Stamina will be your downfall at higher BPM. Going into the higher 200's while using your left/right hand for the majority rhythm will hurt and require practice.
ST - Offbeat patterns like doubles and quads can be annoying because you will start patterns/maintain rhythm on your opposite hand sometimes.
ALT - Finishers will usually destroy your constant alternating note flow/rhythm unless the finisher has a break after it. But more dense patterns with finishers will be a pain.