basically the guns are the same, stag arms is I believe more "mil-spec" then armalite but for a canadian I think it all comes down to what you like better as far as name....
the 2 stage trigger is a big bonus as it will cut your trigger pull down a little... but most users of the AR15 are happy with the stock trigger when using the rifle as a black rifle is intended to be used, if you plan on building a precision rifle out of it then by all means go ahead and get a 2 stage rifle.
Service wise you have picked the two top dealers of ar15's in canada, both stand behind their product and both have an exceptional record of going above and beyond when it comes to helping customers and honouring any warrenty issues.
Looking at online prices as posted by each dealer
Stag 2R - $1385
Armalite M15A4CB - $1195
Stag 2L - $1425 (LEFT HAND EJECT)
Now looking at the prices you would assume the armalite is cheaper, BUT the stag 2R/2L comes with an Arms 40L BUIS which brings the prices closer.... stag also comes with a hard case and a few other do dad's in thier as well ( I believe even a shirt... ?), also there is no mention of 2 stage trigger for that model I listed. Stag Arms will drop a 2 stage giselle trigger in for you if you want for additional $$ and gisselle is considered top notch.
If you want a left handed rifle then you haveno other option but a STAG, and frankly either way right or left I would buy a stagarms from armseast anyday as the service is great. (not saying service from john is not as great, I just love the deer

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