I'm a Canon guy, so I'm of no use to tell you what you want to hear. But I'd like to point out that every lens ever made is a series of trade offs between cost, performance, speed, build quality, etc... Whatever works, man. Only you will know. If a lens isn't working for you, replace it. Otherwise, ignore the forums and get on with shooting. I personally love my fast 85mm and I use it a lot, but that doesn't mean you need one.