CWW,
I have the Windvest and I had the Slipstreamer. If you want something you will use sparingly or just less than half the time you ride, get the SS-10 Viper. It works just fine and is easy as pie to remove , no tools needed. However I will bet that just as I found out you will like riding with the shield on and won't want to remove it.
If that is the case go with the Windvest, immediatly and save the $65 extra you would speend buying both.
I had never ridden with a shield and found that with the riding position on our bikes it is WAAAAAAAAAAy more comfortable with a shield.
I gave the SS to my neighbor and he has been very happy with it for a while now.
Food for thought.
Johnny