I like motion triggering. Always on sounds great until you find something out of place or whatnot and you want to go back through the video to try to find the evidence - watching countless hours of video at that point gets tired fast, trust me.
With motion detection you're not recording stuff for nothing, and it makes sorting through the crap easier if you actually need the footage.
With motion detection you're not recording stuff for nothing, and it makes sorting through the crap easier if you actually need the footage.