There is no reason to buy the latest, first and foremost there are no clients that even support 4x4, what is available is 1x1 and 2x2. You do not gain anything from buying the latest because the clients you have at home are at most AC clients, the speed does not get higher but it can be lower than what you get with AC. The only one to profit from it is the manufacturer who makes money on people's ignorance.