My 2bros has been very good along with their EFI. You would be better off with a power commander EFI controller. If you are looking for the best then you should read up on getting a full exhaust system or starting with a slip-on that you will later be able to add a header to such as FMF.
You will not be disappointed with a 2bros exhaust but I must say I wish I would have gone to a slip-on that would at least leave me with an option of adding a header.