Aside from the poor decision to implement a carbine port we have seen failures due to the minor diameter ahead of the chamer.
even w/o failures barrels are cooked faster.
A barrel should never be of less diameter than the gas block section.
Carbine barrels, fancy M4 style cuts and 1/2" threads are a big mistake.
Some units with power and money have ordered before with a bit more comon sense but still lots of room for improvement.
Again, I don't find any single reason for buying M4 style cut barrels but several reasons to stay away from them.
Lilja barrel with larger section and fluting w/o compromising the minor diameter. Special order from the Navy seals.
Personally I think the profile is great but I like mid port and 5/8 threads for added accuracy. Lothar Walter will cut you one with
a matched bolt for less money. ARP has something very similar called socom better price but w/o flutes but then melonited that is nice too. Either way much better than chromed barrels. Also with 5/8 threads. the 1/2" threads should be always avoided.
People spend all sort of cash in expensive handguards and gas blocks, fancy stocks when a barrel is so important for accuracy and reliability.