My vote and before and after photos
Tim is right. This is a topic that has generated much discussion.
My new (to me) boat came with Poliglow on it. The previous owner has used it for years. In my opinion, if you are looking for a fast and easy solution to have a shiny hull that looks great from 10 feet away it is the way to go. The toughest step is the first one. To have it look nice you still need to clean and buff your hull otherwise you just end up with a shiny dirty hull. Then you use the supplied clean and apply five coats. Application is a breeze. It is literally like waxing your kitchen floor. I use an extension pole and the head supplied threads right onto it. By the time you finish your first coat it is usually dry enough to start your next coat. The next season you just use white scotch brite to clean off any marks on it when you wash the hull. You will likely be surprised and pleased in most cases to find that the marks are actually on the coating, not the boat itself. Then you do 2-3 coats. It takes me about an hour to do three coats on my 30 footer once it is cleaned and prepped. It still looks good, but after about 4 years of poliglow it is getting to the point where I should probably strip it and start from scratch, mostly because you can get streaks in the poliglow if you don't maintain a wet edge so it can self level a bit before it drys. Apparently the previous owner rushed things one year. Over 4 years the streaks seem to have accumulated and the tape stripes on the hull also need replacing badly. I plan on stripping the poliglow to replace the tape stripes to ensure I get good adhesion to the hull.
It was actually pretty funny last year. Three guys were busting their humps cleaning an waxing a forty forter next to me. It took them over eight hours. In six hours, to the astonishment of one of the three, I washed my deck, the hull, left and had lunch, came back two hours later with a beer I was offered while I was chatting with some others in the yard, applied my three coats of poliglow and left. When I left he was still walking around my boat admiring the shine.
I have posted two photos that are quite similar. One is from the previous owner in which it appears that there is no poliglow on the boat yet (sticker on hull says 05). Note that the stripes are all intact still too. The second is the summer of 2008, a few days after poliglow was applied. In particular, look at the reflection of the bollards against the middle of the hull. The third photo on stands gives you another look at the shine.
Regarding John's post, I don't think I would apply it while the boat is on the water, certainly not for the initial application. For annual maintenance application it is probably less problematic. The instructions say that if it rains while you are coating it you can get spots in the coating that will dry out, but no doubt having salt involved complicates matters.