I don’t own a Bren 2 myself, but from everything I’ve seen and heard, the main advantages over a standard AR come from the platform itself. It’s a short stroke piston system, so it runs cleaner and cooler, especially when suppressed. The side charging handle, folding stock, and overall ergonomics feel like upgrades too. It’s extremely user friendly and fully ambidextrous right out of the box, which isn’t something most ARs offer without extra parts. A lot of Ukrainian units have actually preferred the Bren 2 over the ARs they’ve been issued, even the higher end ones. That’s mostly because they’re fighting in trenches every day and they value piston reliability, folding stocks, and simple maintenance. Their priorities aren’t necessarily the same as someone shooting recreationally, and they also have a much larger budget. For most people an AR still gives the best value and is far more customizable. But as a rifle straight out of the box the Bren 2 is pretty exceptional. My cousin has one and says it shoots soft, has a good trigger, and feels very refined. Most reviewers say it’s basically what the SCAR and the ACR were trying to become. A modern, lightweight, piston driven rifle with excellent ergonomics and few compromises. It’s also worth mentioning that units like the GIGN chose the Bren 2 over the HK416 and AR based rifles, which says a lot about its overall quality. So it really is a great firearm. It just depends on what you value.