The 10mm Ethos delivers: 100° apparent field (50% larger in area than 82° Naglers), comfortable eye-relief, (accepts DIOPTRX eyesight astigmatism correctors), distortion correction, high contrast and on-axis sharpness for planetary viewing. It is the "do-it-all" eyepiece perfect for all scopes that can utilize this focal length. And, "filling the hole" between the 13mm and 8mm makes it the ideal centerpiece for a 17mm/10mm/6mm Ethos set.
An important benefit of the combination of large apparent field of view and shorter focal length is that for a given field in the sky, higher magnification results in a darker sky background. Fainter stars become visible and more detail is seen on all deep sky objects. Ethos provides another big magnification/contrast jump, yielding dramatic views simply not previously possible in any telescope. With the smaller exit pupil, eyesight limitations are also reduced.
In addition to matching all the key performance criteria of its 13mm sibling, its lighter weight and smaller diameter makes the 10mm more suitable for use with a binocular viewer.