I'm in tech school right now and my internet connection is horrid. Otherwise I'd do the research myself. I'm looking to replace my bushmaster upper with something of more quality (and not made of plastic ). I was looking at Spikes Tactical 16" M4 upper (Here). Any companies I should shy away from? Is there any piston driven upper that you guys think is better? I'm looking to stick to the 16" barrel length and a piston style system. This would mostly be home defense / paper punisher. It's going on a rock river lower fwiw.