I stayed with the 2.0 lenses when I was building my system. They are heavier and larger than the 2.8 ones, and yet the 2.8 ones have a good reputation for lighter weight and better quality because they have fewer elements (I guess this would be in flare-inducing conditions where the number of elements is noticeable).
Originally Posted by Chris Nielsen
So if acquiring an OM system, I'd recommend the lighter/smaller wides, for price and because less weight is more important for me these days (I'm a backpacker).
But the 85mm f/2.0 is a good portrait lens that I often carry.