I’m working in a Cubase 8 Pro project. I have a track where I want to fade the volume down to zero over four bars.

I figured out that I can do it by adding Volume automation to that track. I can also do it by recording Volume CC MIDI events to the track, which I did by setting the track to Record and moving a slider on my XF. (I know I could also use a Job on the XF, but I’m concentrating on Cubase for the moment.)

My question is, what’s the trade-off? Is one way definitely better than the other? Does it depend on the possible situations? Which situations would that be?

I found this, which says that you can apparently switch back and forth between MIDI and automation relatively easily.

Yes, that’s a good article by SOS.

It depends what you want to do exactly, but for fading a track I would always use volume automation of some type and never MIDI CC’s.

As it happens I usually do it on the audio file after recording using Cubase or Wavelab, leaving the MIDI original in case I want to change things at any time.

MIDI Volume automation is CC7.  With many music libraries these days volume automation is often combined with CC1 Modulation and CC 11 Expression. It doesn’t matter whether you play them in or write them in in the Key Editor....just personal preference. For volume fades though, most people tend to draw them. Automation is also quite useful for things like panning.