I only own one rifle, a MK18.
SBRs dont have the reliability issues they used too, firearm manufacturers have worked out the issues. the people who do have issues usually arent familiar enough or patient enough to fix the issues. My MK18 with its 10.3" barrel works flawlessly suppressed or unsuppressed, in semi auto and full auto.
You need to pick what rifle is best for YOU! i personally dont need long range capability, certainly no more than 100 yards so for plinking, and home defense a MK18 made perfect sense. If you like to engage targets beyond 100 yards you might want to look into a 11.5, 12.5 or even a 14.5 barrel but honestly at 14.5 why the hell even bother with a SBR, if you go through the NFA hassle it better be worth it unless youre reducing significant weight and length from the gun dont waste your time or money.
Oh, and having owned a Mk18 for awhile now, i find myself thinking "it sure would be nice if this was just a couple inches shorter" plus once you add a suppressor on the end it doesnt feel like a SBR anymore.