It has a reciprocating charging handle, is truly ambidextrous, has a standard buttstock with adjustments for better cheekweld, has no buffer tube which allows for a folding buttstock, is piston driven rather than direct impingement, and was actually designed for the piston system.
A different feature isn't necessarily a better one. Reciting a list of features doesn't make them superior in and of themselves, it's the ability to do something in a measurable superior way compared to some other method.
Don't forget, what the SCAR also does well is have all the M16 enhancements built into the basic platform up front. It's the next step based on the pioneer breaking trail. It didn't invent anything more, just used what has been out there for decades in other firearms.
Name one original, unique design feature of any SCAR that hasn't been sold for years for the AR market. Really.
Including them in one package just makes it an incremental improvement at best. The cost certainly proves it, the law of diminishing returns means you get a piston AR that was at least run through an engineering analysis as a fix up, for twice the price.
That still doesn't justify how much better any one of the listed items might be better, if at all. Reciprocating charging handles get hung up on door jambs or tree trunks, watch that. Shooting off handed is rare, a urban combat or competition range technique most owners never practice. An adjustable buttstock is an institutional compromise, if it's your weapon, either get one the right length, or get used to it like millions of others have successfully done. Being able to run it shorter for body armor, may I ask to see how many 1) own body armor, 2) shoot with body armor? Only mil/LEO do that, a small number of professionals.
Folding buttstock? You have to shoot a weapon accurately with it extended, no one can really shoot from the hip and hit anything. Delaying the time to get a weapon into a ready to use shooting position doesn't sound like an enhancement, it's accepting a compromise because they were hiding in a cramped armored vehicle. That's really a doctrinal issue on low intensity conflict, not a superior feature.
As for being a piston, it's based on assuming it's operation is superior to DI. That argument's been going on for over 45 years, pick which side you want to ignore. It's already apparent someone has - which means they are in denial that a combat weapon used for 45 years in over a dozen conflicts does the job. Pointing that out, all over again, for multiple pages, isn't the point of the thread. 9 million M16/M4/AR15's, with over 20 million trained users in the US alone, won't change some minds. They prefer to work in ignorance.
If you want to spend money for something, go ahead. Folks do that with cars, watches, and knives all day. Justifying the expense is really no one else's business - unless tactical and combat reasons are pushed on a public forum to be examined and questioned. Well, there are good reasons not to, just like spending $4000 on a Rolex doesn't compare to a quality $400 quartz chronograph. You will get more for your money with the less expensive watch, you won't get the social enhancement of wearing a Rolex.
It's a choice, but it doesn't mean it's a proven superior in tactical use, and it will not make the owner superior, either.
That takes hard work, developing skill, and the expense of training and ammo.