Vizio has split the M-Series into multiple segments in 2019. This is the M658-G1, which RTings calls part of the M8. This is brighter and has more dimming zones than the M6 and M7 M-Series models you will find elsewhere.
Be careful not to buy the other 65" M Series on the Costco site for the same price – it is the M7 model. Be sure to buy the M658-G1 for the same price.
The RTings review for this lineup is a review of this exact model:
Vizio's page for more info:
From Costco's Site: Price valid through 6/30/20
. While supplies last.