I just installed a Gen 3 MI and I really like it. There are no teeth on the barrel nut to contend with so tightening to spec is easier. I haven't found a slimmer rail system that I like better.
Midwest Industries Gen 3 Lightweight M-Lok http://www.midwayusa.com/product/23...htweight-gen-3-m-lok-handguard-ar-15-aluminum
Magpul MOE Fixed Carbine Stock: http://www.midwayusa.com/product/69...-fixed-carbine-ar-15-lr-308-carbine-synthetic
Midwest Industries Gen 3 Lightweight M-Lok http://www.midwayusa.com/product/23...htweight-gen-3-m-lok-handguard-ar-15-aluminum
Magpul MOE Fixed Carbine Stock: http://www.midwayusa.com/product/69...-fixed-carbine-ar-15-lr-308-carbine-synthetic