I started playing halo when H2 came out and have always played on Recon, yet with so many new abilities and all usable buttons Recon is really hard to use with the emphasis on the smart link and the fact that the ground pound controls are all on one side of of the remote. I think with all of the new abilities, that layouts should be able to be customized even if by allowing for two buttons to be swapped due to personal preference so players don’t have to switch over to completely new layouts.
The new dashboard coming out (Nov 12?) has button mapping.
Controller remapping I believe will be available when Win 10 for Xbox drops on Nov 12th. 
Controller Remapping with Windows 10 for Xbox One