Those of us who use both know that both conductors work just fine when used properly. I have had no problems with aluminum stranded conductors and I have read that today\\\'s chemical composite of aluminum conductors is not the same as that of yesteryear so the problem of surface oxidation is allegedly less. I prefer copper simply because it is faster and easier to install since it is smaller for the same ampacity--though one has to get a loan to buy it. The problem I have had with single-conductor aluminum is that it can not be bent or moved around inside a small outlet box like copper. In working with the old aluminum single conductor, two twists back and forth and it would snap. Another problem was in bending--it was and is very easy to bend a single-conductor aluminum into a super sharp curve (even back onto itself) which could overheat the conductor at the bend--if not just snap it. As far as splicing, I and others have been splicing the two together via cut-up bus bars every since it first came out. Now, the industry is catching up to us in that these cut-up bus bars are now (allegedly listed for such) being sold at the retail level for single-strand aluminum to single-strand copper splicing. Ironically, this is not really new. Burndy rectangular connectors listed for copper and aluminum splicing (14 gauge to 6 gauge) have been out for many, many years as well as mini split-bolt connectors (Madison ASB-10) that are rated for aluminum to copper (#16-10). Thus I have no problems with either copper or aluminum.