reread
I've re-read this thread and noted some things I missed the first time.
Don't be misled by the phrasing in post #2 about bullet weights and twist rates. A 1:9 twist barrel should certainly stablize the next step up above 62's, the well respected 68-69 gr BTHP match slugs. Both Hornady and Sierra state as much in their literature and it aligns with my own experience. Granted, that weight projectile is indeed "not much" above the 62 grain weight mentioned in the phrasing, but it is indeed a step up in performance and BC. Read the posted sentence casually and one might be led to believe that 68-69 won't shoot well, but they usually do. Bullet length is the deciding factor in stablity and twist rate discussions, not just weight. A shorter, rounder nosed semi-spitzer weighing as much as 70-75 grains may well shoot OK from a 1:9 due to its shorter length, whereas a long slim BTHP of the same weight likely will not.
Also, there is commentary elsewhere regarding accessories not easily mounted on a Mini. That is indeed true, but there are shooters who do not care a wit whether their semi hi-cap .223 sporter can mount a light, laser, vertical foregrip, red-dot, magnifier, cell phone or TV remote. If one wants to add that to their rifle, more power to them, but each accessory adds weight and bulk and pretty soon, your carbine ain't very carbine like anymore. The Mini appeals to many users who are not concerned with being tactical or having the latest widget on their rifle. ....or ever being to add any.