The Standard for max field 2 superwide views
The 35mm PO is the sharpest, best corrected maximum field stop 2 superwide angle (60-70 degree) eyepiece I have looked through. Competitors include the Meade 40mm Superwide, and UO 40mm 7/70 Koenig.
Pincushion distortion is noticable, but doesnt detract.
Glasses wearers: Eye relief is considerably less than advertised - eye lens is set deep into housing, making glasses on viewing less than comfortable (I had a machinist modify the top of my eyepiece). Edge sharpenss without glasses suffers (for highly myopic or slightly astigmatic eyes).
If you use with the TV Big Barlow (why would you?), the PanOptic Barlow Interface can be used to correct some minor vignetting that most people wouldnt notice.