I sold my HK416 (civie version) before they got banned in Canada and I still miss it. Yes, the recoil was a bitch (and it's heavy.) But I'd rather deal with that than the inherent reliability problems of a DI system. I've had failures on DI ARs but I've never had a failure on any piston system (HK, SIG, AK) that was caused by the gun itself. My only failures on the 416 were due to the aftermarket magazine, which I stopped using, or the occasional dud primer. I actually stopped bothering to even clean my gun, because it was pointless. And we're not even talking about HK's barrel life, which is practically infinite.
The fact is that most militaries trust the piston-system for a good reason, despite the cost of higher recoil and weight. The most important metric when it comes to firearms is reliability, much more than speed. Americans have a bias towards DI, but a lot of its own warfighters still admit that it can never be as reliable as pistons. You can't be pushing hot gases and fouling in the receiver and expect it to be as reliable as a piston. It's just physics.
With that said, I'll easily admit that any DI AR is a lot more fun to shoot than the 416, because DI feels like a laser by comparison. There's barely any recoil, which is especially important when you only weigh 160lbs like me. My 416 would literally be pushing me back on my heels even with good posture. And my forearms and shoulders would kill me after every range session because it's heavy. The learning curve on a piston system is much higher, but that also forces you to be a better shooter and focus on the fundamentals. I'd still pick piston systems over DI any day.
IMHO, 1-man IPSC-type competions are pointless for infantry/SOFs, it's a waste of taxpayer bought ammo. They could have given them simunition or even paintballs and made them plan and execute a force-on-force operation against each other.
100% agree with you. I have put down some rounds through AR-15s and I have a G36 (same piston system as HK416) and my experience is the same as yours (live Canada as well).
DI AR-15s are extremely soft shooting and very light, the recoil is noticeably smaller than a piston AR or G36. My AR-15 is a 16 inch model and my G36 is the 18 inch barrel, so G36 weighs more than AR-15 and it still recoils' more.
Started owning and shooting guns almost a decade ago and as I get more experienced what I look for in a gun has definitely changed over the years.
Now, I'd rate reliability as the top 1 consideration. If the gun can shoot every time I pull the trigger, and it eats all the ammo I can give it under any type of situation (even when there is dirt in the magazine), and can still perform consistently after putting it through a couple hundred rounds in one sitting, that will be a good gun. On the surface this may not seem like a harsh requirement, but surprisingly a lot of guns cannot consistently do that in the field.
In addition to being able to shoot consistently, another aspect of reliability I'd consider as key is how easy it is to clear a jam. Although rare, I've had a experience where a poor quality bullet casing gets stuck in the chamber and it is impossible to get out with a knife (actually broke the tip of my knife). Luckily it was a SKS so I can grab the charging handle on the bolt and smack the living f**k out of it and helped to clear the jam on the spot. If that's a AR-15, the location and shape of the charging handle will not allow me to do that.
After reliability, imo, the second most important factor to a gun is overall ergonomics. This includes not only the location of fire select/safety, magazine release, bolt release, but also the overall profile/size of the gun and its weight. What I have found over the years is that overall profile of the gun is really important! Tar-21 is arguably a better made gun compared to Type 97, but its overall bulkiness and awkward profile makes it very difficult to handle compared to the slim profile of Type 97, and type 97 just shoots so much more comfortably than a Tar-21. I have similar complaints about the G36 as well. It is a nice gun, but it is super bulky as well, and it is simply awkward to handle. Thus, having a compact and slim design for the overall profile is just as important as having the fire selector/mag release/bolt release at the right spot. It is not easy to design a gun that is comfortable to shoot all day long!
The 3rd consideration becomes modularity, basically how easy it is to swap out parts, or make modifications to the gun.
The 4th consideration is overall cost of the gun, I think being valued appropriately is important. There is no need to over-engineer a basic piece of kit, being cheap to produce and offer the bang for the buck is a lot more important than the pointless pursuit of performance while ignoring how much it costs to produce the gun.
Performance of the gun (accuracy and penetration power) is very relevant, but that is another topic in of it self and I am not too familiar with these topics so will offer no discussion here.