Oh, and PS, All the CF also uses the Browning HP more than anything else. For the most part, only JTF2, Submariner Force Protection details and Navy Boarders are using SIG. The Submariners also use HK in the form of the MP5.
The CF uses the Hi Power because we don't have the funds to outfit and retrain every member who may require a sidearm. We also used the Iltis when the US was using the HMMVW. "What army is using what" is not a great scale to judge effectiveness.
PS: Funny how the latest CP course required any CF member who applied to have plenty of experience with the Sig. Must be just JTF guys applying...
Original Poster: IMHO, the H&K MR223 is overpriced. This rifle is different from the HK416, and has a different purpose. This in no way reflects on the HK416, which happens to carry a price tag a lot lower than the MR223.
Look at it this way...
A Ferrari is overpriced. It's not like you can legally drive 220mph in Canada, it only seats 2, and is going to be in the shop for awhile for standard fixes. But it does look pretty cool, draws chicks in, and you can brag about it.
A Honda Civic is a way better way to go, it will go as fast you need it to, carry 5 people, is easily repaired, and is a helluva lot cheaper.
Transfer that over to rifles...
The H&K MR223... you're never going to fire full auto, or suppressed. You will not be able to find spare parts if anything goes wrong, warranty is going to be next to non-existent. You will not be engaging armed threats beyond the scope of a silhouette target or xbox. BUT! You can take cool hi res pics and post them on Gunnutz, and be Johnny cool at the range. As for drawing chicks in, guns are not a great way to do that.
Any normal "AR-15" (Armalite, Stag, DPMS, etc.) will be interchangeable with anything else out there, and most companies usually have a pretty good warranty setup... even in Canada. They will function almost flawlessly for what you need it for. They are still very reliable, even in "high threat environments"

. You will save about 3k to put towards cool guy accessories or lots of ammo. BUT! You will be just like everybody else on the internet.