A copy and paste from the RFL Forum.

To all: I have had a DX6 for a while with multiple BR6000s and all is good.

I just got 2 DX6is with stock AR6200 RX and 2 additional BR6000s. I have encountered the DX6i binding to BR6000 problems reported here and on the UK forums. One of them will eventually bind after 30-40 seconds. The other will not bind at all to a BR6000. With the old reliable DX6 all BR6000s bound in seconds. The problem is the DX6i. Both DX6is bind to their AR6200 in seconds