Yep, I think that, unless you have a short barrel and/or a "can", the sub-sonics don't do much in a 16" carbine that the 110/115/125s do way better. BTW, Ballistically, the 300 BLK (7.62x35) is a ballistic clone of the original Sturm Gewehr STG-44's 7.92x33, and almost equal to the 7.62x39. What's not to like?
WOW, can you imagine a STG-44 copy in 300 BLK?????? I'd get a second mortgage on the house for that!