Got a set of them on my Monarch II. What sold me was I went to change the oil after a trip out west and found a big chunk over an inch around and over a 1/16 deep missing from the front of one of the aquashields. Whatever smacked it probably wouldve taken out the Missus leg. Right there they earned their keep in my eyes. I have an aquaintance who has a 1500 with no shields and his wife complains especially in construction zones about dust and debris blowing on her lower legs. To me its a personal choice but it really finishes off the look of the trike at least in my eyes.
Get them. Don't even think about it, just get them. Adds to looks, they are practical and they keep your feet warm. Without them your Wing just looks like you have a big fat rear end. IMHO