A friend bought a Ruger to shoot while he figured out how to make his AR 9mm work. When he got the AR straightened out, he pretty much retired the Ruger, saying 22 years in the Army left him proficient with the AR.
Okay, if I were picking a rifle to fight with I'd take a AR, M16, M4. I've only been using them for near 60 years. Everything with those are second nature.
However, if it's 100 yds or closer I wouldn't feel underarmed with a Ruger, Kel Tec, or Hi Point 9mm carbine.