IMO risers for AR's is one area where different brands in the same price range are the same quality. My opinion is based on mounting optics at work for two years.
Even though I don't care for the Nikon M-series they work. The reason I don't care for them is they are a bigger pain to install as others and don't look as sturdy. I said "look" because I've never had one come back. I'm a Warne fanboy but prefer the Burris in this instance. I like the six screw per ring set-up though I haven't had an experience that it's better than two or four screws. And of course as a rule we aren't talking about heavy recoiling rifles here. I also like the fact that with the PEPR you have a choice of smooth or picatinny ring upper. I have a mini red dot mounted on top of the scope on my AR and also on my son's AR. For some people the feature is a nonstarter.
There is no question the LaRue and the other higher priced options are better quality than what I have, especially when "Return to Zero" is a requirement. It is not a requirement for my use though. The only time I'd remove the optic would be to use the iron sights due to optics failure.