A receiver is a receiver, for the most part. Ordering one from Larue Tactical isn't going to make you a SUPER AR. It's probably, on scale, 10% better than anything else on the market that isn't from another name brand company ( Les Baer, Sabre Defense, D & L Sports ).
Is it "better"? Maybe, maybe not. Is it going to make your weapon any better than one that was put together by someone who knows what they are doing and what it takes to make the damn thing run? Probably not.
Is a Larue Tactical full build better than a production line gun like one from the "Tier Two" or "Tier Three" companies? I would say attention to detail would lead towards yes.
If you are building it yourself - the receiver is merely a piece to hold the key components.
It's your money, but I would rather spend it on the parts that REALLY matter as opposed to just a name brand receiver....