How do theese compare to the more popular and expensive systems out there?

Look at this comparison;

[url]http://www.ar15.com/forums/topic.html?b=3&f=12&t=147348[/url]

Its not about the RRA quadrail, but unless mistaken, their quadrail is VERY similar to the Oly FIRSH. Looking quikly at the differences between the two, I would probably preffer the FIRSH system between the two, b/c it incorporates a couple of tension screws at the rear of the system to further secure it into place. Neither of them will lock as solidly as a SIR, FFRAS, or RAS II, so I would preffer any of those over the FIRSH or QuadRail, but if the cost of these better units will prevent you from purchasing one, the  FIRSH is about the best FF rail systems in its price range.

Stominnorman,

I just got a RRA quadrail today and the system seems very solid. I am not sure how it attaches to the upper reciever but the portion that mates to it looks very strong.  As new-arguy mentioned it might not be as solid as a SIR or a RAS II but it will work perfect for my needs. When I am finished with the system my optics (ACOG) will be mounted on the reciever. The vertical grip and light will be on the quadrail so keeping zero is a non issue.  It does not come with any rail covers so make sure you track them down when you buy unless you are using a vertical fore grip.  

If I find it has any shortcomings in the coming months I'll post back here, but right now it looks like it is the perfect setup for my needs.

Thanks for the update!

Post lots of pictures when you get it set up.

[img]http://members.cox.net/daphotoguy/DPMS_Q.jpg[/img]