I spoke to a gentleman named Claudio at Briley. It looks like their service is more cost efficient and eliminates the time installing parts. They quoted me $270 plus $15 for the parts and service.
I haven't seen a review, but I told him I would use my M4 for home defense, training, and local competitions. I was most worried about trigger malfunctions and the trigger re-engagement. He stated they haven't had an issue with the parts installed and the trigger engagement is far quicker.
I'm considering sending my trigger group next month.