My experience is that the Stag rifles are solid guns. I don;t own one except for a lower but acquaintances at the range liked them and they functioned well from what I saw. I have BCM, LMT and PSA rifles but would not hesitate to get a Stag for a good price.
When you read the M4Carbine chart, be sure to read Rob's disclaimer as well. The Chart merely rates each brand according to how well they implement the milspec. Do you even need milspec? Perhaps if you run your rifle hard in classes or depend on it as a primary defense arm. Or if you run a full auto or suppressed carbine.
How much does it matter if the front sight is parkerized underneath? It is in the milspec so it gets rated in the chart. Do you really want the castlenut staked if you are going to change the buttstock out? But that is also part of the milspec. Precision shooters may prefer a regular steel barrel, but milspec says chrome lined bore; is that what you need or want? Milspec says it should be 1:7 twist barrel rifling, is that best for your needs?
In other words, do as Rob suggests, do not follow the milspec Chart blindly. Know what you want the rifle to do and how you will use it, then get the brand/model with the features that best support that use.
If you don't run your rifle hard as mentioned above, then a lot of brands will do very well. Rock River Arms has a lot of configurations, and many of the lower parts kits sold by the big names are DPMS kits. Stag would be a fine one as well. Plus upgrading the extractor parts will go along way to increase reliability and it is fairly cheap.
