Hehe, just to go against the grain, go for 915! (Particularly if you have a darker car.)

Also, I know that a lot of people say that they don't see a difference between LSPs, and I won't dispute their word - but factors such as lighting conditions, the color of the car, and even individual differences in visual acuity can all play a part in whether you see those differences or not. In my case, I certainly feel that there is a difference, at least on my bright red Yaris, between the bright, mirror-like shine of Collinite 845, and, say, the deep, almost iridescent glow of Dodo Juice Rubbishboy's Juiced Edition I have on the car right now.