The last two classes I've attended there were more 1301T than the M4 my assumption is cause the combo of lower priced and people are hearing accounts of reliability.The M4 reputation is unquestionable but there are many that will shy away because of the cost. When it comes to either one having issues there were none. I've noticed other shooter having issues with the 1100 & a few of the M4 clones. I emphasized the weight of 1301 because between the two obviously the M4 is heavier. In a control environment like a course take into account the weather, age, physical conditioning, and how long the course is will determine how motivated the person will be after second or third day of an 8hr course. I've lend them both to several people to do a course and all said the recoil is more manageable with the M4 but the weight drained the desire to keep shooting. Imagine adding the stress of your life or love ones in danger that alone adds more fatigue depending on your training and physical fitness because the heart rate may be going 1k miles a beat.