I went in to my local camera store to purchase the Nikkor 85mm f/1.4 AF-S. I have been renting this lens for a while and I am so impressed by it's quality, sharpness and consistency that I was pretty dead set on it despite the hefty price tag. However, it was suggested that I consider investing in the Tamron 85mm f/1.8 or the Sigma 85mm f/1.4 before taking the plunge for the Nikon. I know that only the Sigma has image stabilization but I would prefer an overall sharper lens to this feature. I realize that the Tamron is only a 1.8, but at less than half the price, how much flexibility am I sacrificing by losing a stop (portraits)? Any helpful feedback would be appreciated. I would rather make the best investment over saving money on the initial purchase.