There's nothing I can add to what has already been written about the ES 17mm 92-degree eyepiece in other reviews across the web. The image is sharp across the view (at least in mine) and the contrast and resolution is excellent. If you're considering purchasing this eyepiece, I suggest you do so. The Double Cluster is amazing and I could easily resolve the Trapezium in M42.
And Don provides customer service second to none. The minute I placed the order I received an email confirmation and later a personal note from Don that the eyepiece was shipped. You can't beat that.