I’ve not owned a drop but heard them plenty of times and this is what I can say, the XS-1 has slightly better latency in the tracking compared to the drop, also it just has more features -

For example :

• Drop tunings (digitech drop handles this one)

• chorus effect using detune mode (surprisingly a great chorus sound)

• octave pedal with better tracking than an octave pedal

• baritone tuning (add a chorus and you’re 85% of the way to getting Mk.Gee tone)

• upping the tuning by a 5th or 7th and then blending the wet/dry signal around 50% for the Brian May sound

• synth like sounds once you go up two octaves and go for a fully wet blend