I received my standard-size Utopia backrest about September 10th and have since put over 1000 miles on the bike and I can say without reservation that I love the backrest!
It's comfortable and doesn't feel at all restrictive. It took a few stops on my first ride to get it adjusted and there were a couple of adjustment "tweaks" after that, but long rides have been a real pleasure since installing this backrest. The attached picture wasn't taken to show the backrest specifically, but it's kinda visible. Should I take another that shows the backrest better I'll be sure to post the picture.
The big thing is that I do like the size of this backrest over the much smaller backrest that was on my Vegas 8-Ball and granted, we're talking about two entirely different bikes but, having that extra support has, for me, really made a positive difference in riding comfort.