After some minimal research and confirmation from several respected forum members, I just switched over to Amsoil. The guy I bought the bike from used HD products. I don't have a mechanical back ground to offer up any technical facts to support as I'll leave that to some of the more controversial "which oil is best" threads here on the forum, but I can tell a marked difference in my bike with the Amsoil synthetic in both holes.
It sounds better, idles better, more responsive, and after riding about 6 hours in 85 degree Texas heat today, it was running much cooler. Also probably the biggest difference I felt was shifting gears. This was my first oil change since purchasing the bike so I was only used to the feel of it as I purchased it. And today it was a different bike. Shifting gears offered a noticeable difference with this synthetic in it.
I've got no ties to Amsoil, don't sell it, and can't tell you why it's better, but proofs in the pudding and I am more than impressed with it.