One of the reasons you'll get a lot of opinions on this is just personal experience. I've put them back on the hives and I've put them out in the yard. I've done both many times. Both work most of the time and putting them on a strong hive works most all of the time, without setting off too much robbing. But sometimes, in a dearth, and whatever other particular conditions contribute, they get into a robbing frenzy. This is more likely with them out in the open.
I usually put them 100 yards or so from the hives and at least 20 or 30 yards from the door to the house. I only made the mistake of putting them by the back door once.