ORIGINAL: Chris True
The purpose of the two seperate receivers isn't interefence but to ensure an RF opaque portion of the airframe doesn't get between you and your TX.
Bingo. Any one receiver is plenty if the antennas are aligned right and there is no gigantic obstruction.
But you need the 4 to ensure that your antenna pattern is optimum in all orientations. Most cell phones have at least 2 antennas as well; cell base stations usually have antennas in different orientations as well. Curious as to why Spektrum did not use 2 radios/antenna on the handheld transmitter (THAT would have cut the number of available slots in half) we had to do that, I guess theirs is working well with one.