The scan rate isn't typically the worst factor, which is usually between 120-300hz (meaning a max additional latency of 3 - 30ms), but rather deriving meaning from that data is. Filtering in a noise-free environment typically adds a few scan frames of latency, which is what puts devices in the 60-120ms of latency, and a noisy environment (i.e. plugged in to a cheap charger) can easily up that to a few hundred ms of latency.