The Scar was selected after extensive testing for issue to SOCOM. The MWS is a specialty weapon for distance precision.

Its like comparing a Ford Mustang to a Ford F150. They serve really different purposes.

I don't care for highly specialized rifles. I prefer more "specialized infantry rifles". The SCAR-H with a proper optic fits this role well, and can do most everything a "dedicated marksman's rifle" can do out to about 600 yards.

Everyone likes to post pictures of 3 shot groups that are clustered into a single ragged hole. These are bench fired clusters under ideal conditions, and frankly if you want to prove a rifle's (or your) ability show me ten FIVE shot groups.

Real world use is totally different than internet hype.

In applications beyond punching paper on a sunny day at the range there are many variables that make it nearly impossible to capitalize on a sniper rifle system (without having been trained as a Scout Sniper)....

1) You almost never have a stable platform. Shooting is often unexpected / snap unless sniping.

2) You have no control over the weather.

3) You're probably shooting from a fouled bore. It might not just be powder residue.

In the end, the SCAR has a free-floated hammer forged barrel and AR type bolt lugs. This gives plenty of accuracy for your above average shooter. This is especially true with a Geiselle Super Scar Trigger. I have one in my Heavy, and will probably put one in the Light.

My Scar Heavy has a Trijicon TA-11H G308 ACOG.
My Scar Light has a Trijicon TA-31 RSR ACOG.

I don't like DI systems for anything other than range toys. In fact, I just shipped both of my Colt LE901-16S (the 308 Modular AR) to a dealer a few weeks ago.

I'll keep a Colt AR, because I've continuously owned AR15s since 1984. However, my serious go-to gun is a SCAR.