I know it's not a true build but I have a complete RRA lower with a two stage trigger that I picked up brand new before the scare started for $300. I am deciding between finishing it with either a RRA mid-length standard upper which who knows when will be available, or a DD upper that I can have in hand next month. The DD is an extra $400 but it's a free float. My questions are: 1. Which upper should I go with? 2. Am I crazy to throw a DD upper on an RRA lower or is that a pretty good match? From what I've found I will be far from the first person to do so. 3. Should I sell the RRA lower and try to get my hands on a complete DD rifle or is there very little difference in lowers when you are talking about the quality of RRA and DD? We all know these are hard times and many people are taking what they can get but I am looking to build this into a quality AR. I have an RRA and love it. I was originally planning on putting an RRA upper on this lower but then found the DD for a good price. I am only looking for constructive conversation, no brand bashing.