Not sure the reset time on the Orvibo, but the Xiaomi are fixed in hardware at 1 minute. So if you're moving during that minute, nothing will happen. True that they are not as sensitive as many others. You need multiple to cover a moderately sized area.
You can lower their reaction time with a fairly simply hack, but it only works on HE. The motion sensors that I later moved to the Aqara Gateway had to have the "hack" removed, because they will not work with the Aqara Gateway when the hack is in place.
