easier to do backend flash with btcable or cobb

I am looking at the instructions on how to do a backend flash with a BT Cable. it looks difficult and confusing to me. I have also looked at the instructions with using the cobb, it seems so much easier. Can anyone tell me if it really is that much easier....also, does bms still send me the maps to put on the cobb or do i get them off bimmer boost?