Between armband and wristband, I believe the difference would be negligible. If it does change, I'd say you'd gain steps.
I'm actually kinda worried about my intake now. I've hit my summer stride, which, this week, averages out to under 1000 cal/ day, closer to 750. The macros are right, on average. I'm eating until not hungry (not full or stuffed, just not hungry) for lunch and dinner. I'm burning closer to 1500/ day, according to my wristband.