2" Konigs/Erfles & fast Newtonians

I am looking for feedback for several 2" eyepieces in conjunction with a Newtonian system in the f/4.9 class. Any comments on how well the Orion Optilux, Omcon Erfles, Antares Erfles, and 2" UO Konigs work with the faster mirrors in your experience?

Thanks!
Steve

They are very bad for edge sharpness if you are used to using them in . . say . . an f/10. Although, some are better than others, and some people actually like the 35mm Omcon erfle better than the 35mm Panoptic.