Crisp views with good contrast on slower optical systems (f/9 +), or when barlowed on faster systems (f/5). Afov IS about 35*, and I feel Eye Relief is slightly shorter than the stated 16mm, it is still on the comfortable side of tight without glasses. Far better ER than Plossls, Orthos and other Monos in the same focal length. Wearing glasses was an issue using this ocular. One more thing, the Burgess 10mm Ultra Monocentric snaps into focus on all of my systems from f/5 to f/15. A lot to really like here in a planetary at an exceptional value!
Full Review of 10mm Monocentric & 24mm Erfle Eyepieces by William A Paolini is available on the website in the Downloads section.