I've got a PSA classic kit in my lower right now. While I am looking to upgrade the trigger, the fit and finish of the rest is just fine. I do not think your going to be disappointed if you went with a non "milspec". I think that term is way over used in the AR-15 industry. And often times a ploy to get you to spend more money on something just because it says mil spec. But I am by no means an expert on this because Ive only built one lower. But I know enough about it that I wouldn't hesitate to buy a PSA classic again..