Agreed.
In theory the faster twist barrels (1 in 7 or 1 in 8) in .223 will stabilize the heavier 69 grain and up to even 80 grain .223 bullets with higher ballistic coefficients. The great advantage in those heavier and longer bullets is bucking the wind and greater stability at long range (over 300 yards and up to 600 yards). If you are usually shooting at 250 yards and less then you do not NEED a 1 in 7 twist barrel nor do you NEED to shoot 69 grain or heavier bullets. You can still use the same barrel and shoot lighter bullets, but you may give up some accuracy at shorter ranges (100 yards)compared to a slower twist barrel. Still probably "minute of coyote" as they say but maybe not minute of angle with lighter loads. Now this comes form John Holliger at White Oak Armory who recommended his 1 in 12 twist match barrel for 200 yards and under shots and low 50ish grain bullets.
The comments about trying differnt bullets /ammo is spot on as each barrel has its own prefences. I have a 20 inch 1 in 9 twist Bushmaster V Match and can shoot most 50 to 60 grain bullets, some a little better than others for groups of 1 inch or less at 100 yards. I happen to like the Hornady V Max bullets (50, 55 and 60 grain)for their accuracy and excellent terminal effect. (I find the Black Hills ammo in .223 a very good factory load. Blue or red box doen't sem to matter. But some soft points group almost as well for me when paper punching. I have not shot FMJ bullets at coyotes (like the standard 55 grain or 62 grain military rounds). I wonder if they might not expand enough and just pass through. Obvioussly your shot placement is most important with any round.
I tried some 40 -50 grain bullets but I did not think they shot as well for my barrel (i.e., groups at 100 yards.) But guys here use them (lighgter bullets) and they put coyotes down.
Your results may differ. Nobody can say what your barrel will shoot best.
If nothing else it gives you an excuse to put some more rounds down range as you try different loads. Maybe a buddy will reload for you if you do not reload. Buy some different bullets or factory loads and keep a log book or save targets.