Certainly echo Clive's endorsement of this eyepiece. We didn't get a great deal of clear sky that night, but before I pulled down the 25" we were able to get a look at NGC2070 and compare the 17mm type 4 Nagler and the Nikon monster. Obviously it would be fairer to compare the equivalent Ethos, but since I'm I spec wearer I don't have one of those. With the Ethos' I have used in the past I can't generally see the field stop, but the Nikon has slightly more eye-relief and I could.
Otherwise, the image was extremely well corrected and rather sharp. Definitely need to spend more time looking through it
Can't remember if I used it when I was tracking down ESO257-19 that night or not - would have been a good test to see if all those extra surfaces affected the light throughput...
Cheers,
Andrew.