So I am at work and I text my wife that the LGS is having a sale on Sigs and the M400 is on sale. She texts me back you should go pick one up! I'm not sure if it's the pregnancy hormones or what but is the M400 a decent AR platform. Oh and I'm looking at getting it in 5.56. Am at work so I can't do much research right now. Thanks for any info.