I have got a J&T/Double Star 16" 6.5 Grendel with CAR handguards. This is the heavy profile Chrome Moley barrel and I think it shoots good. I normally shoot off a Harris bipod or off hand and can't tell a significant change in POI. Granted I don't really shoot with a tight sling torquing on the barrel. I have shot factory A-Max out to 600 yards off my bipod with rear bag off the back of a pickup truck with MOA or less hits. The rifle is generally 1.5-2" or less at 100 with most any load but Wolf steel case 100 grain FMJ.
I also have a 20" H-Bar 5.56/223 Colt that shoots way better than I can and a 16" chrome lined 5.56/223 Bustmaster heavy contour barrel which shoots really good, neither of which are free floated. Me personally, I'd rather have a free floated light weight barrel but the heavier contour barrels I don't mind mine that are not free floated.
I also have a 20" H-Bar 5.56/223 Colt that shoots way better than I can and a 16" chrome lined 5.56/223 Bustmaster heavy contour barrel which shoots really good, neither of which are free floated. Me personally, I'd rather have a free floated light weight barrel but the heavier contour barrels I don't mind mine that are not free floated.