Regarding the distance discussion, there have been several studies, whether in academia, or seasoned beekeeper and others.
Here is a link to a Dr. Tom Seeley presentation regarding how swarms decide on their optimum hive: http://breeze.cce.cornell.edu/p1vpc8e0m5w/?launcher=false&fcsContent=true&pbMode=normal
This URL is a video that launches in Adobe Connect from your web browser. Much of it is quite basic, but it is, I believe, a great companion to the Dr. Justin Schmidt material cited in the first post of this discussion. The video is about an hour long.
I note that, this spring, a 15,000-bee swarm took up a tree branch that was intertwined with a chain link vehicle gate. (The gate to an apiary had been opened such that it was pressed against the tree branches, so when the bees took up their swarm cluster position, the chain link gate ran right through their cluster, about 5 feet off the ground.) Rather than disturb them, we set up a swarm trap about 4 feet away. I simply rolled a large trashcan there, about 48" high, placed a medium super there with empty plastic frames, plus one frame of drawn comb and a pheromone lure. Surprisingly, it took them 3 days until they decided to occupy the box. Had it taken longer, we would have needed to close the gate. I'm confident they would have re-constituted the cluster and carried on scouting out potential cavities, but I'm glad I didn't put them through the exercise.
Two things I gather from this:
1. They didn't accept the super-conveniently-located, super-well-provisioned cavity until they had gone through the whole process of comparing various potential sites and had reached consensus on the close one, and
2. They were only in so much of a hurry to make their decision.
A little more background: They came to the area as a cut-out from an exposed hive hanging from a tree branch ten feet off the ground. 100% of their brood comb, including new eggs in fresh comb were installed into the box in which the colony was placed. They abandoned the box, leaving all their brood unattended. Because they were a cut-out, and little of their honey was available to them, they had little honey to take with them as a departing swarm. The branch/gate on which they temporarily settled was only 50 feet from the box they abandoned. They are now prospering--explosively building comb and rearing brood.
Happy Swarm trapping,