I have 2 prisms and one chimney, my favourite is the 45 degrees one, yet the 90 comes handy when tripod height is bigger (I'm a rather short guy with 175cm) and my chimney is great when is snowing and/or for night photography.

They are all great tools, depends of the different scenarios you're faced with, it's more or less like optics, employ the right one for the job in hands.