As usual with these things, I'd been a bit concerned about whether the alarm triggering was sensitive enough, that has no adjustment. I've just used the alarm for the first time this morning outside Sainsburys.
Came out with shopping, forgot about the alarm it being first time, started to undo one pannier clasp and there was an immediate warning beep reminding me.
So yes, it's sensitive enough.
I'd previously programmed it from the standard two warning beeps down to one, and I think I'll leave it at that, one warning's enough before blasting offender's ears!
.